ARMWARE RFC Archive <- RFC Index (1401..1500)

RFC 1480

Obsoletes RFC 1386

Network Working Group                                          A. Cooper
Request for Comments: 1480                                     J. Postel
Obsoletes: 1386                                                June 1993

                             The US Domain

Status of this Memo

   This memo provides information for the Internet community.  It does
   not specify an Internet standard.  Distribution of this memo is

Table of Contents

   1.  Introduction ................................................  2
       1.1  The Internet Domain Name System.........................  2
       1.2  Top-Level Domains.......................................  3
       1.3  The US Domain ..........................................  4
   2.  Naming Structure ............................................  4
       2.1  State Codes ............................................  8
       2.2  Locality Names..........................................  8
       2.3  Schools ................................................ 10
       2.4  State Agencies.......................................... 15
       2.5  Federal Agencies ....................................... 15
       2.6  Distributed National Institutes......................... 15
       2.7  General Independent Entities............................ 16
       2.8  Examples of Names....................................... 17
   3.  Registration ................................................ 20
       3.1  Requirements ........................................... 20
       3.2  Direct Entries ......................................... 21
       3.2.1   IP-Hosts............................................. 21
       3.2.2   Non-IP Hosts ........................................ 21
       3.3  Delegated Subdomains ................................... 24
       3.3.1   Delegation Requirement............................... 26
       3.3.2   Delegation Procedures ............................... 28
       3.3.3   Subdomain Contacts................................... 29
   4.  Database Information......................................... 30
       4.1  Name Servers ........................................... 30
       4.2  Zone files ............................................. 30
       4.3  Resource Records ....................................... 31
       4.3.1   "A" Records ......................................... 32
       4.3.2   CNAME Records ....................................... 32
       4.3.3   MX Records .......................................... 33
       4.3.4   HINFO Records ....................................... 33
       4.3.5   PTR Records ......................................... 33
       4.4  Wildcards .............................................. 34
   5.  References .................................................. 35

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RFC 1480                     The US Domain                     June 1993

   6.  Security Considerations ..................................... 35
   7.  Authors' Addresses .......................................... 36
   Appendix-I:  US Domain Names BNF................................. 37
   Appendix-II: US Domain Questionnaire ............................ 42


   1.1 The Internet Domain Name System

   The Domain Name System (DNS) provides for the translation between
   hostnames and addresses.  Within the Internet, this means translating
   from a name such as "", to an IP address such as
   "".  The DNS is a set of protocols and databases.  The
   protocols define the syntax and semantics for a query language to ask
   questions about information located by DNS-style names.  The
   databases are distributed and replicated.  There is no dependence on
   a single central server, and each part of the database is provided in
   at least two servers.

   The assignment of the 32-bit IP addresses is a separate activity.  IP
   addresses are delegated by the central Internet Registry to regional
   authorities (such as the RIPE NCC for Europe) and the network

   To have a network number assigned please contact your network service
   provider or regional registration authority.  To determine who this
   is (or as a last resort), you can contact the central Internet
   Registry at Hostmaster@INTERNIC.NET.

   In addition to translating names to addresses for hosts that are on
   the Internet, the DNS provides for registering DNS-style names for
   other hosts reachable (via electronic mail) through gateways or mail
   relays.  The records for such name registrations point to an Internet
   host (one with an IP address) that acts as a mail forwarder for the
   registered host.  For example, the host "" is
   registered in the DNS with a pointer to the mail relay
   "".  This type of pointer is called an MX record.

   This gives electronic mail users a uniform mail addressing syntax and
   avoids making users aware of the underlying network boundaries.

   The reason for the development of the domain system was growth in the
   Internet.  The hostname to address mappings were maintained by the
   InterNIC in a single file, called HOSTS.TXT, which was FTP'd by all
   the hosts on the Internet.  The network population was changing in
   character.  The time-share hosts that made up the original ARPANET
   were being replaced with local networks of workstations.  Local
   organizations were administering their own names and addresses, but

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RFC 1480                     The US Domain                     June 1993

   had to wait for the NIC to make changes in HOSTS.TXT to make the
   changes visible to the Internet at large.  Organizations also wanted
   some local structure on the name space.  The applications on the
   Internet were getting more sophisticated and creating a need for
   general purpose name service.  The idea of a hierarchical name space,
   with the hierarchy roughly corresponding to organizational structure,
   and names using "." as the character to mark the boundary between
   hierarchy levels was developed.  A design using a distributed
   database and generalized resources was implemented.

   The DNS provides standard formats for resource data, standard methods
   for querying the database, and standard methods for name servers to
   refresh local data from other name servers.

   1.2  Top-Level Domains

   The top-level domains in the DNS are EDU, COM, GOV, MIL, ORG, INT,
   and NET, and all the 2-letter country codes from the list of
   countries in ISO-3166.  The establishment of new top-level domains is
   managed by the Internet Assigned Numbers Authority (IANA).  The IANA
   may be contacted at IANA@ISI.EDU.

   Even though the original intention was that any educational
   institution anywhere in the world could be registered under the EDU
   domain, in practice, it has turned out with few exceptions, only
   those in the United States have registered under EDU, similarly with
   COM (for commercial). In other countries, everything is registered
   under the 2-letter country code, often with some subdivision.  For
   example, in Korea (KR) the second level names are AC for academic
   community, CO for commercial, GO for government, and RE for research.
   However, each country may go its own way about organizing its domain,
   and many have.

   There are no current plans of putting all of the organizational
   domains EDU, GOV, COM, etc., under US.  These name tokens are not
   used in the US Domain to avoid confusion.

   Currently, only four year colleges and universities are being
   registered in the EDU domain.  All other schools are being registered
   in the US Domain.

   There are also concerns about the size of the other top-level domains
   (especially COM) and ideas are being considered for restructuring.

   Other names sometimes appear as top-level domain names.  Some people
   have made up names in the DNS-style without coordinating or
   registering  with the DNS management.  Some names that typically
   appear are BITNET, UUCP, and two-letter codes for continents, such as

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RFC 1480                     The US Domain                     June 1993

   "NA" for North America (this conflicts with the official Internet
   code for Namibia).

   For example, the DNS-style name "KA7EEJ.CO.USA.NA" is used in the
   amateur radio network.  These addresses are never supposed to show up
   on the Internet but they do occasionally.  The amateur radio network
   people created their own naming scheme, and it interferes sometimes
   with Internet addresses.

   1.3  The US Domain

   The US Domain is an official top-level domain in the DNS of the
   Internet community.  The domain administrators are Jon Postel and Ann
   Westine Cooper at the Information Sciences Institute of the
   University of Southern California (USC-ISI).

   US is the ISO-3166 2-letter country code for the United States and
   thus the US Domain is established as a top-level domain and
   registered with the InterNIC the same way other country domains are.

   Because organizations in the United States have registered primarily
   in the EDU and COM domains, little use was initially made of the US
   domain.  In the past, the computers registered in the US Domain were
   primarily owned by small companies or individuals with computers at
   home.  However, the US Domain has grown and currently registers hosts
   in federal government agencies, state government agencies, K12
   schools, community colleges, technical/vocational schools, private
   schools, libraries, city and county government agencies, to name a

   Initially, the administration of the US Domain was managed solely by
   the Domain Registrar.  However, due to the increase in registrations,
   administration of subdomains is being delegated to others.

   Any computer in the United States may be registered in the US Domain.


   The US Domain hierarchy is based on political geography.  The basic
   name space under US is the state name space, then the "locality" name
   space, (like a city, or county) then organization or computer name
   and so on.

   For example:


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RFC 1480                     The US Domain                     June 1993

   There is of course no problem with running out of names.

   The things that are named are individual computers.

   If you register now in one city and then move, the database can be
   updated with a new name in your new city, and a pointer can be set up
   from your old name to your new name.  This type of pointer is called
   a CNAME record.

   The use of unregistered names is not effective and causes problems
   for other users.  Inventing your own name and using it without
   registering is not a good idea.

   In addition to strictly geographically names, some special names are
   used, such as FED, STATE, AGENCY, DISTRICT, K12, LIB, CC, CITY, and
   COUNTY.  Several new name spaces have been created, DNI, GEN, and
   TEC, and a minor change under the "locality" name space was made to
   the existing CITY and COUNTY subdomains by abbreviating them to CI
   and CO.  A detailed description follows.

   Below US, Parallel to States:

   "FED" - This branch may be used for agencies of the federal
   government.  For example: <org-name>.<city>.FED.US

   created directly under the top-level US.  This branch is to be used
   for distributed national institutes; organizations that span state,
   regional, and other organizational boundaries; that are national in
   scope, and have distributed facilities.  For example:

   Name Space Within States:

   "locality" - cities, counties, parishes, and townships.  Subdomains
   under the "locality" would be like CI.<city>.<state>.US,
   CO.<county>.<state>.US, or businesses. For example:

   "CI" - This branch is used for city government agencies and is a
   subdomain under the "locality" name (like Los Angeles). For example:

   "CO" - This branch is used for county government agencies and is a
   subdomain under the "locality" name (like Los Angeles).  For example:

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RFC 1480                     The US Domain                     June 1993

   "K12" - This branch may be used for public school districts.  A
   special name "PVT" can be used in the place of a school district name
   for private schools.  For example: <school-name>.K12.<state>.US and

   "CC" - COMMUNITY COLLEGES - This branch was established for all state
   wide community colleges.  For example: <school-name>.CC.<state>.US.

   established for technical and vocational schools and colleges. For
   example: <school-name>.TEC.<state>.US.

   be used for libraries only.  For example:  <lib-name>.LIB.<state>.US.

   "STATE" - This branch may be used for state government agencies.  For
   example:  <org-name>.STATE.<state>.US.

   "GEN" - GENERAL INDEPENDENT ENTITY - This branch is for the things
   that don't fit easily into any other structure listed -- things that
   might fit in to something like ORG at the top-level.  It is best not
   to use the same keywords (ORG, EDU, COM, etc.) that are used at the
   top-level to avoid confusion.  GEN would be used for such things as,
   state-wide organizations, clubs, or domain parks.  For example:



                            |  US   |
              |        |        |       |        |
           +-----+  +-----+  +-----+  +-----+  +-----+
           | FED |  | DNI |  | TX  |  | SD  |  | CA  |
           +-----+  +-----+  +-----+  +-----+  +-----+


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RFC 1480                     The US Domain                     June 1993

                                |  CA |
          |            |        |            |             |
        +-----+     +-----+  +-----+  +-------------+   +-----+
        | K12 |     | CC  |  | TEC |  | LOS ANGELES |   | LIB |
        +-----+     +-----+  +-----+  +-------------+   +-----+
          /   \       /|\      /|\          /|\           /|\
   +--------+ +---+  +---+  +--------+  +----------+    +------+
   |sch dist| |PVT|  |SJC|  |WM TRADE|  |pvt school|    |MALIBU|
   +--------+ +---+  +---+  +--------+  +----------+    +------+
      /|\      /|\
   +--------+ +--------+
   |sch name| |sch name|
   +--------+ +--------+


                                |  CA |
                      |            |            |
                   +-------+   +--------+    +-----+
                   | STATE |   |DISTRICT|    | GEN |
                   +-------+   +--------+    +-----+
                     /|\          /|\          /|\
                   +--------+   +------+   +---------+
                   |CALTRANS|   |SCAQMD|   |domain pk|
                   ---------+   +------+   +---------+

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RFC 1480                     The US Domain                     June 1993


                                |  CA |
                   |                                   |
         +-------------------------+           +----------------+
         |       LOS ANGELES       |           |  SANTA MONICA  |
         +-------------------------+           +----------------+
          /  |          |       /|\                |       /|\
         /   |          |        |                 |        |
     +---+ +--+        +--+  +-----------+       +--+     +---+
     |bus| |CI|        |CO|  | pvt school|       |CI|     |bus|
     +---+ +--+        +--+  +-----------+       +--+     +---+
            /\          |                          |
           /  \         |                  +------------+
          /    \        |                  |HARBOR GUARD|
         /      \       |                  +------------+
    +-----+ +-----+   +-----+ +----+
    |FIRE | |ADMIN|   |PARKS| |FIRE|
    +-----+ +-----+   +-----+ +----+

   2.1  State Codes

   The state codes are the two letter US Postal abbreviations. For
   example: "CA" California.

   2.2  Locality Names

   Within the state name space there are "locality" names, some may be
   cities, some may be counties, some may be local names, but not
   incorporated entities.

   Registered names under "locality" could be like:

     <hostname>.CI.<locality>.<state>.US   ==>  city gov't agency
     <hostname>.CO.<locality>.<state>.US,  ==>  county gov't agency
     <hostname>.<locality>.<state>.US      ==>  businesses

   In the cases where the locality name is a county, there is a branch
   under the locality name, called "county" or "CO", that is used by the
   county government.  Businesses are registered directly under the
   locality name.

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RFC 1480                     The US Domain                     June 1993

   Under the city locality name space there is a "city" or "CI" branch
   for city government agencies.  As usual, businesses and private
   schools may register directly under the city name.

   In the case where there is both a county and a city with the same
   locality name there is no problem, since the names will be unique
   with the "CO" or "CI" keyword.  In our area the county has a fire
   department and the city has its own fire department.  They could have
   names like:


   Cities may be named (designated) by their full name (spelled out with
   hyphens replacing spaces (e.g., Los-Angeles or Fort-Collins), or by a
   city code.  The first choice is the full city name.  In some cases it
   may be appropriate to use the well-known city abbreviation known
   throughout a locality.  However, it is very desirable that all users
   in the same city use the same designator for the city.  That is, any
   particular locality should have just one DNS name.

   Some users would like names associated with a greater metropolitan
   area or region like the "Bay Area" or "Tri-Cities".  One problem with
   this is that these names are not necessarily unique within a state.
   The best thing to do in this case is to use the larger metropolitan
   city in your hostname.  Cities and counties are used.

   Should all the names be obvious?  Trying to do this is desirable and
   also impossible.  There will come a point when the obviously right
   name for an organization is already taken.  As the system grows this
   will happen with increasing frequency.  While ease of use to the end
   user is desirable, a higher priority must be placed on having a
   system that operates.  This means that the manageability of the
   system must have high consideration.

   The reason the DNS was created was to subdivide the problem of
   maintaining a list of hosts in the Internet into manageable portions.

   The happy result is that this subdivision makes name uniqueness
   easier and promotes logical grouping.  What is a "logical grouping"
   though, always depends on the viewer.

   Many levels of delegation are needed to keep the zone files
   manageable.  Many sections of the name space are needed to allow
   unique names to be easily added.

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RFC 1480                     The US Domain                     June 1993

   Way back in the olden days, when the Internet was invented, some
   thought that an 8-bit network number would be more than enough to
   number all the networks that would ever exist.  Today, there are over
   10,000 networks operating in the Internet, and arguments are made
   about the doubling time being 2 years versus 4 years.

   One concern is that things will continue to grow dramatically, and
   this will require more subdivision of the domain name management.
   Maybe the plan for the US Domain is overkill on growth planning, but
   there has never been overplanning for growth yet.

   When things are bigger, names have to be longer.  There is an
   argument that with only 8-character names, and in each position allow
   a-z, 0-9, and -, you get 37**8 = 3,512,479,453,921 or 3.5 trillion
   possible names.  It is a great argument, but how many of us want
   names like "xs4gp-7q".  It is like license plate numbers, sure some
   people get the name they want on a vanity plate, but a lot more
   people who want something specific on a vanity plate can't get it
   because someone else got it first.  Structure and longer names also
   let more people get their "obviously right" name.

   2.3  Schools

   K12 schools are connecting to the Internet and registering in the
   Internet DNS.  A decision has been made by the IANA (after
   consultation with the new InterNIC Internet Registry and the Federal
   Networking Council (FNC)) to direct these school registrations to the
   US domain using the naming structure described here.

   There is a need for competent, experienced, volunteers to come
   forward to act as third and perhaps fourth level registries and to
   operate delegated portions of the DNS.

   There are two reasons for registering schools in the US Domain.  (1)
   uniqueness of names, and (2) management of the database.

     1. Name Uniqueness:

        There are many "Washington" high schools, only one can be
        "Washington.EDU" (actually none can be, since that name is used
        by a University.  There will be many name conflicts if all
        schools attempt to register directly under EDU.

        In addition, in some districts, the same school name is used at
        different levels, for example, Washington Elementary School and
        Washington High School.  We suggest that when necessary, the
        keywords "Elementary", "Middle", and "High" be used to
        distinguish these schools.  These keywords would only be used

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RFC 1480                     The US Domain                     June 1993

        when they are needed, if the school's name is unique without
        such keywords, don't use them.

     2. Database Management:

        One goal of the DNS is to divide up the management of the name
        database in to small pieces.  Each piece (or "zone" in DNS
        terminology) could be managed by a distinct administrator.
        Adding all the high schools to the EDU domain will make the
        already large zone file for EDU even larger, possibly to the
        point of being unmanageable.

   For both these reasons it is necessary to introduce structure into
   names.  Structure provides a basis for making common names unique in
   context, and for dividing the management responsibility.

      The US Domain has a framework established and has registered many
      schools already in this structured scheme.  The general form is:


            For example: Hamilton.LA-Unified.K12.CA.US

   Public schools are usually organized by districts which can be larger
   or smaller than a city or county.  For example, the Portland school
   district in Oregon, is in three or four counties.  Each of those
   counties also has non-Portland districts.

   It makes sense to name schools within districts.  However districts
   often have the same name as a city or county so there has to be a way
   to distinguish a public school district name from some other type of
   locality name.  The keyword "K12" is used for this.

   For example, typical K12 school names currently used are:


   These names are generally longer than the old alternative of shorter
   names in the EDU domain, but that would not have lasted long without
   a significant number of schools finding that their "obviously
   correct" name has already been used by some other school.

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RFC 1480                     The US Domain                     June 1993

   When there are many things to name some of the names will be long.
   In some cases there may be appropriate abbreviations that can be
   used.  For example Hamilton High School in Los Angeles could be:


   If a school has a number of PCs, then each PC should have a name.
   Suppose they are named "alpha", "beta", ... then if they belong to a
   school named "Lincoln.High.Lakewood.K12.CA.US" their names would be:


   The K12 subdomain provides two points at which to delegate a branch
   of the database to distinct administrators -- the K12 Administrator
   for each state, and the district administrator for each district
   within a state.

   The US Domain Administrator will delegate a branch of the US domain
   to an appropriate party.  In some cases, this may be a particular
   school, a school district, or ever all of K12 for a state.

   The responsibility for managing a K12 branch or sub-branch may be
   delegated to an appropriate volunteer.  We envision that such
   delegations of the schools' DNS service may eventually migrate to
   someone else "more appropriate" from an administrative organizational
   point of view.  The "obvious" state agency to manage the schools' DNS
   branch may take some time to get up to speed on Internetting.  In the
   meantime, we can have the more advanced schools up and running.

   Special Schools and Service Units

   In many states, there are special schools that are not in districts
   that are run directly by the state or by consortiums.  There are also
   service units that provide "educational services" ranging from books
   and computers to janitorial supplies and building maintenance.  Often
   these service units do not have a one-to-one relationship with

   There is some concern about naming these schools and service units
   within the naming structure for schools established in this memo.
   There are several possibilities.  For a state with many service units
   creating a "pseudo district" ESU (or whatever, the common terminology
   is in that state) is a possibility.  For example, the Johnson service
   unit could be JOHNSON.ESU.K12.CA.US.  For a state with a few such
   service units (and avoiding conflicts with district names) the
   service units could be directly under K12.  For example,

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RFC 1480                     The US Domain                     June 1993


   The special public funded schools can be handled in a similar
   fashion.  If there are many special schools in a state, a "pseudo
   district" should be established and all the special schools listed
   under it.  For example, suppose there is a "pseudo district" in
   Massachusetts called SPCL, and there is a special school called the
   Progressive Computer Institute, then that school could have the name
   PCI.SPCL.K12.MA.US.  If there are only a few special schools, they
   can be listed directly under K12 (avoiding name conflicts with
   district names).  For example, the California Academy of Math and
   Science is CAMS.K12.CA.US.  CAMS is sponsored by seven schools, the
   California Department of Education, and a University.

   "PVT" Private Schools

   Private schools may be thought of as businesses.  Public schools are
   in districts, and districts provide a natural organizational
   structure for naming and delegation.  For private schools there are
   no districts and they really do operate like businesses.  But, many
   people are upset to think about their children in a private school
   being in a business category and not in K12 with the rest of the
   children.  To accommodate both public and private schools, in each
   state's K12 branch, we've added an artificial district called private
   or "PVT".  This gives a private school the option of registering like
   a business under "locality" or in the PVT.K12.<state-code>.US branch.

   For example:


   A public school "Oak High" in the "Woodward" school district in
   California would have a name like "Oak-High.Woodward.K12.CA.US".

   A private school "Old Trail" in Pasadena, California could have the
   <locality> based name "Old-Trail.Pasadena.CA.US" or the private
   school base name "Old-Trail.PVT.K12.CA.US".

   Some suggest that for private schools instead of a special pseudo
   district PVT to use a locality name.  One reason to use district
   names is that, in time, it seems likely that school district
   administrators will take over the operation of the DNS for their
   district.  One needs to be able to delegate at that branch point.
   One implication of delegation is that the delegatee is now in charge
   of a chunk of the name space and will be registering new names. To
   keep names unique one can't have two different people registering new
   things below identically named branches.

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RFC 1480                     The US Domain                     June 1993

   For example, if there is a school district named Pasadena and a city
   named Pasadena, the branch of the name space PASADENA.K12.CA.US might
   be delegated to the administrator of that public school district.  If
   a private school in Pasadena wanted to be registered in the DNS, it
   would have to get the public school district administrator to do it
   (perhaps unlikely) or not be in the K12 branch at all (unless there
   is the PVT pseudo district).

   So, if private schools are registered by
   <school>.<locality>.K12.<state-code>.US and public schools are
   registered by <school>.<district>.K12.<state-code>.US, there can't be
   any locality names that are the same as district names or the
   delegation of these will get very tricky later.

   If it is all done by locality names rather than district names, and
   public and private schools are mixed together, then finding an
   appropriate party to delegate the locality to may be difficult.

   Another suggestion was that private schools be registered directly
   under K12, while public schools must be under a district under K12.
   This would require the operator of the K12 branch to register all
   districts and private schools himself (checking for name uniqueness),
   he couldn't easily delegate the registration of the private schools
   to anyone else.

   Community Colleges and Technical Schools

   To distinguish Community Colleges and Technical/Vocational schools,
   the keywords "CC" and "TEC" have been created.

   Some School Examples

   Hamilton.High.LA-Unified.K12.CA.US        <== a public school
   Sherman-Oaks.Elem.LA-Unified.K12.CA.US    <== a public school
   John-Muir.Middle.Santa-Monica.K12.CA.US   <== a public school
   Crossroads-School.Santa-Monica.CA.US      <== a private school
   SMCC.CC.CA.US                             <== a community college
   TECMCC.CC.CA.US                           <== a community college
   Brick-and-Basket-Institute.TEC.CA.US      <== a technical college
   Northridge.CSU.STATE.CA.US                <== a state university

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RFC 1480                     The US Domain                     June 1993

   2.4  State Agencies

   Several states are setting up networks to interconnect the offices of
   state government agencies.  The hosts in such networks should be
   registered under the STATE.<state-code>.US branch.

   A US Domain name space has been established for the state government
   agencies.  For example, in the State of Minnesota, the subdomain is

      State Agencies:

      Senate.STATE.MN.US      <== State Senate
      MDH.STATE.MN.US         <== Dept. of Health
      CALTRANS.STATE.CA.US    <== Dept. of Transportation
      DMV.STATE.CA.US         <== Dept. of Motor Vehicles

   2.5  Federal Agencies

   A federal name space has been established for the federal government
   agencies.  For example, the subdomain for the Federal Reserve Bank of
   Minneapolis is MNPL.FRB.FED.US. Other examples are listed below.

      Federal Government Agencies:

      Senate.FED.US   <====  US Senate
      DOD.FED.US      <====  US Defense Dept.
      USPS.FED.US     <====  US Postal Service
      VA.FED.US       <====  US Veterans Administration
      IRS.FED.US      <====  US Internal Revenue Service
      Yosemite.NPS.Interior.FED.US    <====  A Federal agency

   2.6  Distributed National Institutes

   The "DNI" branch was created directly under the top-level US.  This
   is to be used for organizations that span state, regional, and other
   organizational boundaries; are national in scope, and have
   distributed facilities.  An example would be:

      Distributed National Institutes:

      MetaCenter.DNI.US   <====  The MetaCenter Supercomputer Centers

Cooper & Postel                                                [Page 15]

RFC 1480                     The US Domain                     June 1993

   The MetaCenter domain encompasses the four NSF sponsored
   supercomputer centers. These are:

       San Diego Supercomputer Center (SDSC)
       National Center for Supercomputing Applications (NCSA)
       Pittsburgh Supercomputing Center (PSC)
       Cornell Theory Center (CTC)

   The MetaCenter Network will enable applications and services like
   file systems and archival storage to be operated in a distributed
   fashion; thus, allowing the resources at the four centers to appear
   integrated and "seamless" to users of the centers.

   2.7  General Independent Entities

   This name space was created for organizations that don't really fit
   anywhere else, such as state-wide associations, clubs, and "domain
   parks".  Think of this as the miscellaneous category.

   The examples are state-wide clubs.  For example, the Garden Club of
   Arizona, might want to be "GARDEN.GEN.AZ.US".  Such a club has
   membership from all over the state and is not associated with any one
   city (or locality).  Another example is "domain parks" that have been
   established up-to-now as entities in ORG.  For example, there is
   "LONESTAR.ORG", which is a kind of computer club in Texas that has
   lots of dial-in computers registered.  In the US Domain such an
   entity might have a name like "LONESTAR.GEN.TX.US".

   The organizations registered in GEN may typically be non-profit
   entities.  These organizations don't fit in a <locality> and are not
   a school, library, or state agency.  Ordinary businesses are not
   registered in GEN.

   Some suggest that these kinds of organizations are just like all the
   other things and ought to be registered under some <locality>.  This
   may be true, but sometimes one just can't find any way to convince
   the applicant that it is the right thing to do.  One can argue that
   any organization has to have a headquarters, or an office, or
   something about it that is in a fixed place, and thus the
   organization could be registered in that place.

   Some suggest that no token is needed, these entities could be
   directly under the <state-code>.  The problem with not having a
   token, is that you can't delegate the responsibility for registering
   these entities to someone separate from whoever is responsible for
   the <state-code>.  You want to be able to delegate for both name-
   uniqueness reasons, and operational management reasons.  Having a
   token there makes both easy.

Cooper & Postel                                                [Page 16]

RFC 1480                     The US Domain                     June 1993

      General Independent Entities:

      CAL-Comp-Club.GEN.CA.US   <====  The Computer Club of California

      2.8  Examples of Names

      For small entities like individuals or small businesses, there is
      usually no problem with selecting locality based names.

            For example:  Zuckys.Santa-Monica.CA.US

      For large entities like large corporations with multiple
      facilities in several cities or states this often seems like an
      unreasonable constraint (especially when compared with the
      alternative of registering directly in the COM domain).  However,
      a company does have a headquarters office in a particular locality
      and so could register with that name. Example: IBM.Armonk.NY.US

      PRIVATE (business or individual)

      Camp-Curry.Yosemite.CA.US       <====  a business
      IBM.Armonk.NY.US                <====  a business
      Dogwood.atl.GA.US               <====  a business
      Geo-Petrellis.Culver-City.CA.US <====  a restaurant
      Zuckys.Santa-Monica.CA.US       <====  a restaurant
      Joe-Josts.Long-Beach.CA.US      <====  a bar
      Holodek.Santa-Cruz.CA.US        <====  a personal computer


      Senate.FED.US           <====  US Senate
      DOD.FED.US              <====  US Defense Dept.
      DOT.FED.US              <====  US Transportation Dept.
      USPS.FED.US             <====  US Postal Service
      VA.FED.US               <====  US Veterans Administration
      IRS.FED.US              <====  US Internal Revenue Service
      Yosemite.NPS.Interior.FED.US    <====  a federal agency
      MNPL.FRB.FED.US.     <====  US Fed. Reserve Bank of Minneapolis

Cooper & Postel                                                [Page 17]

RFC 1480                     The US Domain                     June 1993


      Senate.STATE.MN.US      <====  state Senate
      House.STATE.MN.US       <====  state House of Reps
      MDH.STATE.MN.US         <====  state Health Dept.
      HUD.STATE.CA.US         <====  state House and Urban Dev. Dept.
      DOT.STATE.MN.US         <====  state Transportation Dept.
      CALTRANS.STATE.CA.US    <====  state Transportation Dept.
      DMV.STATE.CA.US         <====  state Motor Vehicles Dept.
      Culver-City.DMV.STATE.CA.US  <====  a local office of DMV

      DNI  (distributed national Institutes)

      METACENTER.DNI.US       <==== a distributed nat'l Inst.

      GEN (General Independent Entities)

      GARDEN.GEN.AZ.US        <==== a garden club of Arizona

      CITY | CI | COUNTY | CO (locality)

      Parks.CI.Culver-City.CA.US          <====  a city department
      Fire-Dept.CI.Los-Angeles.CA.US      <====  a city department
      Fire-Dept.CO.Los-Angeles.CA.US      <====  a county department
      Planning.CO.Fulton.GA.US.           <====  a county department
      Main.Library.CI.Los-Angeles.CA.US   <====  a city department
      MDR.Library.CO.Los-Angeles.CA.US    <====  a county department

      TOWNSHIP | PARISH (locality)

      Police.TOWNSHIP.Green.OH.US           <====  a township department
      Administration.PARISH.Lafayette.LA.US <====  a parish department

Cooper & Postel                                                [Page 18]

RFC 1480                     The US Domain                     June 1993

      DISTRICT | LIBRARY  (agency)

      SCAQMD.DISTRICT.CA.US                 <====  a regional district
      Bunker-Hill-Improvement.DISTRICT.LA.CA.US <====  a local district

      Huntington.LIB.CA.US                  <====  a private library
      Venice.LA-City.LIB.CA.US              <====  a city library
      MDR.LA-County.LIB.CA.US               <====  a county library


      Hamilton.High.LA-Unified.K12.CA.US      <====  a public school
      Sherman-Oaks.Elem.LA-Unified.K12.CA.US  <====  a public K12 school
      John-Muir.Middle.Santa-Monica.K12.CA.US <====  a public K12 school
      Culver-High.CCSD.K12.CA.US              <====  a public K12 school

      St-Monica.High.Santa-Monica.CA.US       <====  a private school
      Crossroads-School.Santa-Monica.CA.US    <====  a private school
      Mary-Ellens.Montessori-School.LA.CA.US  <====  a private school
      Progress-Learning-Center.PVT.K12.CA.US  <====  a private school

      SMCC.Santa-Monica.CC.CA.US      <====  a public community college
      Trade-Tech.Los-Angeles.CC.CA.US <====  a public community college
      Valley.Los-Angeles.CC.CA.US     <====  a public community college

      Brick-and-Basket-Institute.TEC.CA.US    <== a technical college

      When appropriate, subdomains are delegated and partioned in
      various categories, such as:

       <locality>.<state>.US   =   city/locality based names
              K12.<state>.US   =   kindergarten thru 12th grade
           PVT.K12.<state.US   =   private kindergarten thru 12th grade
               CC.<state>.US   =   community colleges
              TEC.<state>.US   =   technical or vocational schools
              LIB.<state>.US   =   libraries
            STATE.<state>.US   =   state government agencies
           <org-name>.FED.US   =   federal government agencies
           <org-name>.DNI.US   =   distributed national institutes
      <org-name>.GEN.<state>.US. = statewide assoc,clubs,domain parks

      The Appendix-I contains the current US Domain Names BNF.

Cooper & Postel                                                [Page 19]

RFC 1480                     The US Domain                     June 1993


   There are two types of registrations (1) Delegation, where a branch
   of the US Domain is delegated to an organization running name servers
   to support that branch; or (2) Direct Registration, in which the
   information is put directly into the main database.

   In Direct Registration there are two cases: (a) an IP-host (with an
   IP address), and (b) non-IP host (for example, a UUCP host).  Any
   particular registration will involve any one of these three

   3.1  Requirements

   Anyone requesting to register a host in the US Domain is sent a copy
   of the "Instructions for the US Domain Template", and must fill out a
   US Domain template.

   The US Domain template, is similar to the InterNIC Domain template,
   but it is not the same.  To request a copy of the US Domain template,
   send a message to the US Domain registrar (

   If you are registering a name in a delegated zone, please register
   with the contact for that zone.  You can FTP the file "in-notes/us-
   domain-delegated.txt" from, via anonymous FTP.  This
   information is also available via email from RFC-INFO@ISI.EDU
   (include as the only text in the message
   "Help: us_domain_delegated_domains").

   The key people must have electronic mailboxes (that work).  Please
   provide all the information indicated in the "Administrator" and
   "Technical Contact" slots.

   The administrator will be the point of contact for any administrative
   and policy questions about the domain. The administrator is usually
   the person who manages the organization being registered.

   The technical contact can also be administrator, or the systems
   person, or someone who is familiar with the technical details of the
   Internet.  The technical contact should have a valid working email
   address.  This is necessary in case something goes wrong.

   It is important that your "Return-Path" and "From" field indicate an
   Internet-style address.  UUCP-style addresses such as "host1!user"
   will not work.  This is fine within the UUCP world, but not the
   Internet.  If you want people on the Internet to be able to send mail
   to you, your return path needs to be an Internet-style address such
   as: host1! or

Cooper & Postel                                                [Page 20]

RFC 1480                     The US Domain                     June 1993

   It is also possible to register through one of the Internet service
   providers that have established working relationships with the US
   Domain Administrator.

   If everything checks out, the turn around time for registering a host
   is usually a few days.  The name servers are updated anywhere from 12
   to 24 hours later.

   There are two ways to be registered in the US Domain, directly, or by

   3.2  Direct Entries

   Direct entry in the database of the US Domain appeals most to
   individuals and small companies.  You may fill out the application
   and send it directly to the US Domain Administrator.  If you are in
   an area where the zone is delegated to someone else your request will
   be forwarded to the zone administrator for your registration.  Or,
   you may send the form directly to the manager of a delegated zone
   (see Section 3.1).

   3.2.1 IP-Hosts

   These are hosts with IP addresses which correspond to "A" records in
   the DNS database.

   3.2.2 Non-IP Hosts

   Many applicants have hosts in the UUCP world.  Some are one hop away,
   some two and three hops away from their "Internet Forwarder", this is
   acceptable.  What is important is getting an Internet host to be your
   forwarder.  If you do not already have an Internet forwarder, there
   are several businesses that provide this service for a fee, such as
   UUNET.UU.NET (, PSI (postmaster@UU2.PSI.COM)
   and CERFNET (  Sometimes local colleges in your area
   are already on the Internet and may be willing to act as an Internet
   Forwarder.  You would need to work this out with the systems
   administrator as we cannot make these arrangements for you.

   Although we work with UUCP service providers, the Internet US Domain
   registration is not affiliated with the registration of UUCP Map
   entries.  The UUCP map entry does not provide us with sufficient
   information.  If you do not have a copy of the US Domain
   questionnaire template, please send a message to:
   and request one.  See Appendix-II.

Cooper & Postel                                                [Page 21]

RFC 1480                     The US Domain                     June 1993

   The example below is not an appropriate registration for the US Domain.

     #N starl
     #S Amiga 2500; AmigaDOS 2.04; Dillon's AmigaUUCP 1.15D
     #O Starlight BBS
     #C Stephen Baker
     #E starl!sbaker
     #T +1 305 378 1161
     #P 1107 SW 200th St #303B Miami, Fl. 33157
     #L 25 47 N / 88 10 W [city]
     #U mthvax
     #W starl!sbaker (Stephen Baker); Mon Feb 24 19:58:24 EST 1992
      starl        mthvax(DAILY)

   If you are registering your host as a central site for a USENET group
   where other UUCP sites will feed from you, that's fine.  These UUCP
   sites do not need to register.  If however, the other sites become a
   subdomain of your hostname, then we will need to register them
   individually or add a wildcard record. (See Section 4.4. Wildcards).

           For example:

   To use US Domain names for non-IP hosts, there must be a forwarder
   host that is an IP host.  There must be an administrative agreement
   and a technical procedure for relaying mail between the non-IP host
   and the forwarder host.

   Case 1:

   Your host is not an IP host but does talk directly with a host that
   is an IP host.
   +----------+            +---------+            |                 |
   |your-host |---UUCP-----|forwarder|----IP/TCP--|    INTERNET     |
   +----------+            +---------+            |                 |
   "Forwarder" must be an IP host on the Internet.

   You must ask "forwarder" if they are willing to be the Internet
   forwarder for "your-host".

   In the US Domain of the DNS data base there must be an entry like
          "your-host"  MX  10  "forwarder"

Cooper & Postel                                                [Page 22]

RFC 1480                     The US Domain                     June 1993

   This must be entered by the US Domain Administrator.

   In the "forwarder" routing tables there must be information about
   "your-host" with a rule like: If I see mail for "your-host" I will
   send it via uucp by calling phone number "123-4567".

   Case 2:

   In this case your hosts talks to another host that ... that talks to
   an IP host.  In other words, there are multiple hops between your host
   and the Internet.
   +----------+            +---------+            |                 |
   |path-host |---UUCP-----|forwarder|----IP/TCP--|    INTERNET     |
   +----------+            +---------+            |                 |
       |                                          +-----------------+
   |your-host |

   "Forwarder" must be an IP host on the Internet.

   You must ask "forwarder" if they are willing to be the Internet
   Forwarder for "Your-Host".  You must ask "path-host" to relay your

   In the US Domain of the DNS Database there must be an entry like this:

          "your-host"  MX  10  "forwarder"

   This must be entered by the US Domain Administrator.

   In the "forwarder" routing tables there must be information about
   "your-host" with a rule like: If I see mail for "your-host" I will
   send it via UUCP to "path-host" by calling phone number "123-4567".
   and "path-host" must also know how to relay the mail to "your-host".

   Note: It is assumed that "path-host" is already MXed to "forwarder".
   It is not appropriate to ask to MX "your-host" to "path-host" (this
   is sometimes called double MXing).  The host on the right hand side
   of an MX entry must be a host on the Internet with an IP address

Cooper & Postel                                                [Page 23]

RFC 1480                     The US Domain                     June 1993

   3.3  Delegated Subdomains

   Many branches of the US Domain are delegated. There must be a
   knowledgeable and competent technical contact, familiar with the
   Internet DNS.  This requirement is easily satisified if the technical
   contact already runs some other name servers.

   Examples of delegations are K12.TX.US for the Kindergarten through
   12th Grade public schools in Texas, the locality "", or
   the LIB.MN.US branch for the libraries in Minnesota.

   The administrator of the US Domain is responsible for the assignment
   of all the DNS names that end with ".US".  Of course, one person or
   even one group can't handle all this in the long run so portions of
   the name space are delegated to others.

   The major concern in selecting a designated manager for a domain is
   that it be able to carry out the necessary responsibilities, and have
   the ability to do an equitable, just, honest, and competent job.

   The key requirement is that for each domain there be a designated
   manager for supervising that domain's name space.

   These designated authorities are trustees for the delegated domain,
   and have a duty to serve the community.

   The designated manager is the trustee of the domain for the domain
   itself and the global Internet community.

   Concerns about "rights" and "ownership" of domains are inappropriate.
   It is appropriate to be concerned about "responsibilities" and
   "service" to the community.

   The designated manager must be equitable to all groups in the domain
   that request domain names.

   This means that the same rules are applied to all requests.  All
   requests must be processed in a nondiscriminatory fashion, and
   academic and commercial (and other) users are treated on an equal
   basis.  No bias shall be shown regarding requests that may come from
   customers of some other business related to the manager -- e.g., no
   preferential service for customers of a particular data network
   provider.  There can be no requirement that a particular mail system
   (or other application), protocol, or product be used.

   There are no requirements on subdomains beyond the requirements on
   higher-level domains themselves.  That is, the requirements are
   applied recursively.  In particular, all subdomains shall be allowed

Cooper & Postel                                                [Page 24]

RFC 1480                     The US Domain                     June 1993

   to operate their own domain name servers, providing in them whatever
   information the subdomain manager sees fit (as long as it is true and

   Significantly interested parties in the domain should agree that the
   designated manager is the appropriate party.

   The US Domain Administrator tries to have any contending parties
   reach agreement among themselves, and generally takes no action to
   change things unless all the contending parties agree; only in cases
   where the designated manager has substantially neglected their
   responsibilities would the US Domain Administrator step in.

   The designated manager must do a satisfactory job of operating the
   DNS service for the domain.

   That is, the actual management of the assigning of domain names,
   delegating subdomains and operating name servers must be done with
   technical competence.  This includes keeping the US Domain
   Administrator or other higher-level domain managers advised of the
   status of the domain, responding to requests in a timely manner, and
   operating the database with accuracy, robustness, and resilience.

   There must be a primary and a secondary name server that have IP
   connectivity to the Internet and can be easily checked for
   operational status and database accuracy by the US Domain

   One of the aspects of having two name servers for each domain (or
   zone), is for robustness.  One concern under this heading is that the
   name service not go out entirely if there is a local power failure
   (earthquake, tornado, or other disaster).

   Name Servers should be in distinctly separate physical locations.  It
   is appropriate to have more than two name servers, but there must be
   at least two.

   For any transfer of the designated manager trusteeship from one
   organization to another, the higher-level domain manager must receive
   communications from both the old organization and the new
   organization that assures the US Domain Administrator that the
   transfer in mutually agreed, and that the new organization
   understands its responsibilities.

   It is also very helpful for the US Domain Administrator to receive
   communications from other parties that may be concerned or affected
   by the transfer.

Cooper & Postel                                                [Page 25]

RFC 1480                     The US Domain                     June 1993

   Delegation of cities, companies within cities, schools (K12),
   community colleges (CC), libraries (LIB), state government (STATE),
   and federal government agencies (FED), etc., is acceptable and

   For a delegated portion of the name space, for example a city, no
   alterations can be made to that name, no abbreviations added, etc.
   unless applied for.

   Sometimes there may be two people running name servers in the same
   city because different portions of the name space has been delegated
   to them.  For example, someone may be delegated the <city>.<state>.US
   name space, and someone else from a state government agency may have
   the .STATE.<state>.US, portion.  For example, Fred may run the name
   servers for Sacramento.CA.US and Joe may run the name servers for
   STATE.CA.US in Sacramento.

   If a company would like to have wildcard records added, or run their
   own name servers in a city that we have delegated name space to, this
   is acceptable.

   Delegation of the whole State name space is not yet implemented.  The
   delegated part of the name space is in the form of:


   3.3.1.  Delegation Requirements

   When a subdomain is delegated, the following requirements must be

      1)  There must be a knowledgeable and competent technical contact,
          familiar with the Internet DNS.  This requirement is easily
          satisified if the technical contact already runs some other
          name servers.

Cooper & Postel                                                [Page 26]

RFC 1480                     The US Domain                     June 1993

      2)  Organizations requesting delegations must provide at least two
          independent (robust and reliable) DNS name servers in
          physically separate locations on the Internet.

      3)  The subdomain must accept all applicants on an equal basis.

      4)  The subdomain must provide timely processing of requests.  To
          do this, it is helpful to have several individuals
          knowledgeable about the procedures so that the operations are
          not delayed due to one persons unavailability (for example, by
          being on vacation).

      5)  The subdomain manager must tell the US Domain Administrator
          when there are changes in the name servers that should be
          reflected in the US Domain zone files, or changes in the
          contact information.

   K12 Administrators

      In the long term, registering schools will be a big job.  So you
      need to have in mind delegating parts of the work to various
      school districts.  If you can delegate every school district in
      the state then you are finished, except for checking that they are
      all operating correctly.  However, initially you will have quite a
      bit to do with educating people, helping them choose names and
      getting name servers arranged.  You are responsible for seeing
      that the naming of schools follow the guidelines suggested in this

      All K12 Administrators will initially be responsible for managing
      the "pseudo district" PVT for private schools.  Private schools
      have the option of registering as <school-name>.PVT.K12.<state>.US
      or as a business under the city based names.

   Locality Administrators

      If you have been delegated a locality subdomain, you will be
      responsible for registering not only businesses directly under the
      locality, but city and county agencies under the "CI" and "CO"
      branches.  When appropriate these branches should be delegated.

      If you want, you may spell out "CITY" instead of "CI" or "COUNTY"
      instead of "CO", but you must be consistent and use only one or
      the other in a given locality.  The whole city government should
      be under one branch.

Cooper & Postel                                                [Page 27]

RFC 1480                     The US Domain                     June 1993

   WHOIS Database

      Only the second and third level delegated name spaces will be
      entered in the WHOIS database.  For example, K12.CA.US would have
      an entry in WHOIS.  Anything under K12.CA.US will not be listed.
      The US Domain Administrator will send the information that you
      supplied on your US Domain template to the InterNIC.  It is the
      hope that in the future, each delegated subdomain will provide
      their own WHOIS directory database for their branch.

   3.3.2  Delegation Procedures

   The procedure that is followed when a subdomain is delegated includes
   the following steps:

      1)  Evaluate the technical contact's experience with DNS.  Make
          sure there is a need for the proposed delegation.  Make sure
          the technical contact has the information about the US Domain
          and the suggested naming structure.  Two contacts with email
          addresses are necessary in case something goes wrong.

      2)  Add the new technical contact to the "us-dom-adm" mailing list
          for distributing updates concerning the US Domain policies and

      3)  Delete any hosts from our zone file that belongs in the newly
          delegated subdomain and make sure they now have the hosts in
          their zone file.

      4)  Send them a copy of the zone file so their initial zone file
          is identical to ours. For example:

      69582   SOA
                                  930119  ;serial
                                  28800   ;refresh
                                  14400   ;retry
                                  3600000 ;expire
                                  86400 ) ;minim

      69582   NS
   85483   A
      69582   NS
     85483   A
      69582   HINFO   Sun 3/60 SunOs
      69582   MX      10
      69582   HINFO   386 Clone DOS
      69582   MX      10

Cooper & Postel                                                [Page 28]

RFC 1480                     The US Domain                     June 1993

        69582   HINFO   UNIX PC UNIX
        69582   MX      10
      69582   MX      10
      69582   HINFO   MacIntosh System 7
      69582   MX      10
       69582   HINFO   386 Clone DOS
       69582   MX      10

      5)  The US Domain zone file must have the following records,
          showing the name, address, email, and phone number of the
          technical contact for the delegated subdomain and the name of
          the delegated name space and the names of the name servers.

            ;Contact:  Joseph Klein (
            ;          Marquette University
            ;          (414) 288-6734
            ;Delegate zone

        604800  NS      SPOOL.MU.EDU.
                            604800  NS      SOPHIE.MSCS.MU.EDU.

            ; A glue record is not needed this time. Glue records are
            ; needed when the name of the server is a subdomain of the
            ; delegated domain.

      6)  Check to see that delegated subdomain name servers are up and
          running, and make sure the delegated hosts are installed in
          their zone file.  Now delete any hosts from the US Domain zone
          file that belongs in the newly delegated subdomain.

      7)  Inform the technical contact of the newly delegated subdomain
          that wildcard records are allowed in the zone file under the
          organizational subdomain but no wildcard records are allowed
          under the "city" or "state" domain.

      8)  Make sure each administrator has a copy of this RFC and
          follows the guidelines set forth.

   3.3.3   Subdomain Contacts

   The number of hosts registered under each subdomain is unknown. See
   Section 3.1 for information on the delegated domains and the

Cooper & Postel                                                [Page 29]

RFC 1480                     The US Domain                     June 1993


   4.1. Name Servers

   Name servers are the repositories of information that make up the
   domain database.  The database is divided up into sections called
   zones, which are distributed among the name servers.  While name
   servers can have several optional functions and sources of data, the
   essential task of a name server is to answer queries using data in
   its zones.  The response to a query can always be generated using
   only local data, and either contains the answer to the question or a
   referral to other name servers "closer" to the desired information.

   A given zone will be available from several name servers to insure
   its availability in spite of host or communication link failure.
   Every zone is required to be available on at least two servers, and
   many zones have more redundancy than that.

   The US Domain is currently supported by seven name servers:


   4.2 Zone Files

   A "zone" is a registry of domains kept by a particular organization.
   A zone registry is "authoritative", that is, the master copy of the
   registry is kept by the zone organization, and this copy is, by
   definition, always up-to-date.  Copies of this registry may be
   distributed to other places and kept in caches, but these caches are
   not authoritative, and may be out-of-date.

   Every zone has at least one node, and hence domain name, for which it
   is authoritative, and all of the nodes in a particular zone are
   connected.  Given the tree structure, every zone has a highest node
   which is closer to the root than any other node in the zone.  The
   name of this node is often used to identify the zone.  The data that
   describes a zone has four major parts:

        1) Authoritative data for all nodes within the zone.

        2) Data that defines the top node of the zone
           (can be thought of as part of the authoritative data).

Cooper & Postel                                                [Page 30]

RFC 1480                     The US Domain                     June 1993

        3) Data that describes delegated subzones, i.e., cuts
           around the bottom of the zone,

        4) Data that allows access to name servers for subzones
           (sometimes called "glue" data).

   The zone administrator has to maintain the zones at all the name
   servers which are authoritative for the zone.  When the changes are
   made, they must be distributed to all of the name servers.

   Copies of the zone files are not available unless you are on the
   Internet.  To look at the zone files use the "dig" program of the DNS
   domain name system.

        dig   @nshost  host-your-checking  axfr

   4.3 Resource Records

   Records in the zone data files are called resource records (RRs).
   The standard Resource records (RR) are specified in STD 13, RFC 1034
   and STD 13, RFC 1035 (3,4).  An RR has a standard format as shown.

                  <name> [<ttl>] [<class>] <type> <data>

   The first field is always the name of the domain record.  The second
   field is an optional time to live field.  This specifies how long
   this data will be stored in the data base.  The third field is the
   address class; the class field specifies the protocol group most
   often this is the Internet class "IN".  The fourth field states the
   type of the resource record.  The fields after that are dependent on
   the Type of RR.  The fifth field is the data field which is defined
   differently for each type and class of data.  Here is a list of the
   current commonly used types:

           SOA     Start of Authority
           NS      Name Server
           A       Internet Address
           CNAME   Canonical Name (nickname pointer)
           HINFO   Host Information
           WKS     Well Known Services
           MX      Mail Exchanger
           PTR     Pointer

Cooper & Postel                                                [Page 31]

RFC 1480                     The US Domain                     June 1993

   What do the fields mean?

           foo.LA.CA.US.    604800    MX   10     Venera.ISI.EDU.
           (1)              (2)       (3)  (4)    (5)

           1)  domain name
           2)  time to live information
           3)  mail exchanger record
           4)  preference value to determine (if more than one
               forwarder) which mailer to use first, lower number
               higher preference
           5)  the Internet forwarding host.

   4.3.1  "A" Records

   Internet (IP) Address.  The data for an "A" record is an Internet
   address in a dotted decimal form.  A sample "A" record might look

              (name)               (A)     (address)

   The name field is the machine name, and the address is the network
   address.  There should be only one "A" record for each address of a

   4.3.2  CNAME Records

   Canonical Name resource record, CNAME, specifies an alias for a
   canonical name.  This is essentially a pointer to the official name
   for the requested name.  All other RRs appear under this official
   name.  A machine named FERNWOOD.MPK.CA.US may want to have the
   nickname ANTERIOR.MPK.CA.US.  In that case, the following RR would be

            (alias nickname)                   (canonical name)

   Nicknames (the name associated with the RR is the nickname) may be
   added for awhile when a host changes its name, usually because it
   moves to another state.  It helps to have this CNAME pointer so if
   any mail comes to the old address it will get forwarded to the new
   one.  There cannot be any other RRs associated with a nickname of the
   same class.

Cooper & Postel                                                [Page 32]

RFC 1480                     The US Domain                     June 1993

   4.3.3  MX Records

   Mail Exchanger records, MX, are used to specify a machine that knows
   how to deliver mail to a machine that is not directly connected to
   the Internet.  For example, is the mail gateway that
   knows how to deliver mail to, but other machines on the
   network cannot deliver mail directly to  These two
   machines may have a private connection or use a different transport
   medium (such as uucp).  The preference value (10) is the order that a
   mailer should follow when there is more than one way to deliver mail
   to a single machine.  The lower the number the higher the preference.

           foo.LA.CA.US.  604800  MX  10  Venera.ISI.EDU.
           foo.LA.CA.US.  604800  MX  20

   4.3.4   HINFO Records

   Host information resource records, HINFO is for host specific data.
   This lists the hardware and operating system that are running at the
   listed host.  It should be noted that a space separates the hardware
   information and the operating system information.  If you want to
   include a space in the machine name you must quote the name.  Host
   information is not specific to any class, so ANY may be used for the
   address class.  There should be one HINFO record for each host.       HINFO       VAX-11/780      UNIX
                                   (Hardware)      (Operating System)

   The official HINFO types can be found in the latest Assigned Numbers
   RFC, the most recent edition being STD 2, RFC 1340 [9].  The hardware
   type is called the Machine Name, and the software type is called the
   System Name.

   The information users supply about this is often inconsistent or
   incomplete.  Please follow the terms in the current "Assigned

   4.3.5  PTR Records

   A Domain Name Pointer record, PTR, allows special names to point to
   some other location in the domain data base.  These are typically
   used in setting up reverse pointers for the special IN-ADDR.ARPA
   domain.  PTR names should be unique to the zone.
             (special name)                  (real name)

Cooper & Postel                                                [Page 33]

RFC 1480                     The US Domain                     June 1993

   A PTR record is to be added to the IN-ADDR.ARPA domain for every "A"
   record registered in the US Domain.  These PTR records need to be
   added by the administrator of the network where the host is
   connected.  The US Domain Administration does not administer the
   network and cannot make these entries in the DNS database.

   4.4  Wildcards

   The wildcard records are of the form "*.<anydomain>", where
   <anydomain> is any domain name.  The wildcards potentially apply to
   descendents of <anydomain>, but not to <anydomain> itself.

   For example, suppose a large company located in California with a
   large, non-IP/TCP, network wanted to create a mail gateway.  If the
   company was called DWP.LA.CA.US, and the IP/TCP capable gateway
   machine (Internet forwarder) was called ELROY.JPL.NASA.GOV, the
   following RRs might be entered into the .US zone.

     MX      10       ELROY.JPL.NASA.GOV
         *    MX      10       ELROY.JPL.NASA.GOV

   The wildcard record *.DWP.LA.CA.US would cause an MX query for any
   domain name ending in DWP.LA.CA.US to return an MX RR pointing at
   ELROY.JPL.NASA.GOV. The entry without the "*" is needed so the host
   dwp can be found.

   In the US Domain, wildcard records are allowed in our zone files
   under the organizational subdomain (and where noted otherwise) but no
   wildcard records are allowed under the "City" or "State" domain.

       The authors strongly believe that it is in everyone's
       interest and good for the Internet to have each host
       explicitly registered (that is, we believe that wildcards
       should not be used), we also realize that not everyone
       agrees with this belief.  Thus, we will allow wildcard
       records in the US Domain under groups or organizations.
       For example, *.DWP.LA.CA.US.

       The reason we feel single entries are the best is by the mere
       fact that if anyone wanted to find one of the hosts in the
       domain name system it would be there, and problems can be
       detected more easily.  When using wildcards records all the
       hosts under a subdomain are hidden.

Cooper & Postel                                                [Page 34]

RFC 1480                     The US Domain                     June 1993


   [1]  Stahl, M., "Domain Administrators Guide", RFC 1032, SRI
        International, November 1987.

   [2]  Lottor, M., "Domain Administrators Operations Guide" RFC 1033,
        SRI International, November 1987.

   [3]  Mockapetris, P., "Domain Names - Concepts and Facilities",
        STD 13, RFC 1034, ISI, November 1987.

   [4]  Mockapetris, P., "Domain Names - Implementation and
        Specification", STD 13, RFC 1035, ISI, November 1987.

   [5]  Dunlap, K., "Name Server Operations Guide for Bind,
        Release 4.3", UC Berkeley, SMM:11-3.

   [6]  Partridge, C., "Mail Routing and the Domain Name System",
        STD 14, RFC 974, BBN, January 1986.

   [7]  Albitz, P., C. Liu, "DNS and Bind" Help for UNIX System
        Administrators, O'Reilly and Associates, Inc., October 1992.

   [8]  ACM SIGUCCS Networking Taskforce, "Connecting to the Internet -
        What Connecting Institutions Should Anticipate", FYI 16,
        RFC 1359, August 1992.

   [9]  Reynolds, J., and J. Postel, "Assigned Numbers", STD 2,
        RFC 1340, ISI, July 1992.

6. Security Considerations

   Security issues are not discussed in this memo.

Cooper & Postel                                                [Page 35]

RFC 1480                     The US Domain                     June 1993

7. Authors' Addresses

   Ann Cooper
   USC/Information Sciences Institute
   4676 Admiralty Way
   Marina del Rey, CA  90292
   Phone:  1-310-822-1511

   Jon Postel
   USC/Information Sciences Institute
   4676 Admiralty Way
   Marina del Rey, CA  90292
   Phone:  1-310-822-1511

Cooper & Postel                                                [Page 36]

RFC 1480                     The US Domain                     June 1993

                     APPENDIX-I:  US DOMAIN NAMES BNF

   <us-domain-name>    ::= <us-name><dot><us>

   <us-name>           ::= <state-name><dot><state-code> |

   <state-code>        ::= <the two-letter code of a state from the
                            zip code directory>

   <state-name>        ::= <local-name><dot><locality> |
                           <state-agency-name><dot><state> |

   <fed-name>          ::= <the dotted hierarchical name of a US
                            federal government agency>

   <dni-name>          ::= <the dotted hierarchical name of a
                            distributed national institution>

   <locality>          ::= <the full name of a city from the
                             zip code directory> |
                           <a short code name for a city> |
                           <the full name of a county, township,
                            or parish> |
                           <other well known and commonly used
                            locality name>

   <local-name>        ::= <entity-name> |
                           <city-name><dot><city> |
                           <county-name><dot><county> |

   <state-agency-name> ::= <the dotted hierarchical name of a state
                            government agency>

   <regional-agency-name> ::= <the dotted hierarchical name of a
                             special agency or district not an
                             element of the state government and
                             typically larger than a single city or
                             county, for example, the Southern
                             California Air Quality Management District>

Cooper & Postel                                                [Page 37]

RFC 1480                     The US Domain                     June 1993

   <entity-name>       ::= <the dotted hierarchical name of an
                            entity within a city, for example: a
                            company, business, private school, club,
                            organization, or individual>

   <city-name>         ::= <the dotted hierarchical name of a city
                            government agency>

   <county-name>       ::= <the dotted hierarchical name of a county,
                             township, or parish government agency>

   <local-agency-name> ::= <the dotted hierarchical name of a special
                            agency or district not an element of a
                            city or county government and typically
                            equal or smaller than a single city or
                            county, for example, the Bunker Hill
                            Improvement District>

   <city> ::= "CI" | "CITY"

   <county> ::= "CO" | "COUNTY" | "TOWNSHIP" | "PARISH"

   <dot> ::= "."

   <fed> ::= "FED"

   <dni> ::= "DNI"

   <state> ::= "STATE" | "COMMONWEALTH"

   <agency> ::= "AGENCY" | "DISTRICT" | "K12" | "CC" | "LIB" |
                "GEN"    | "TEC"

   <local-agency> ::= "AGENCY" | "DISTRICT"

   <us> ::= "US"


   Within States:

   "K12" may be used for public school districts.  A special name
   "PVT" can be used in the place of a school district name for
   private schools.

   "CC" may be used only for public community colleges.

Cooper & Postel                                                [Page 38]

RFC 1480                     The US Domain                     June 1993

   "LIB" may be only used by libraries.

   "TEC" is used only for technical and vocational schools and colleges.

   "GEN" is for general independent entities, that is, organizations
   that don't really fit anywhere else (such as statewide associations,
   clubs, and "domain parks").

   "STATE" may be used only for state government entities.

   Below US, parallel to States:

   "FED" is for agencies of the federal government.

   "DNI" is for distributed national institutes; organizations that
   span state, regional, and other organizational boundaries; that
   are national in scope, and have distributed facilities.


   Geo-Petrellis.Culver-City.CA.US         <== resturant

   Joe-Josts.Long-Beach.CA.US              <== bar

   IBM.Armonk.NY.US                        <== business

   Camp-Curry.Yosemite.CA.US               <== business

   Yosemite.NPS.Interior.FED.US            <== federal agency

   Senate.FED.US                           <== US Senate

   DOD.FED.US                              <== US Defense Dept.

   DOT.FED.US                              <== US Transportation Dept.

   MNPL.FRB.FED.US                         <== the Minneapolis branch of
                                               the Federal Reserve Bank

   MetaCenter.DNI.US                       <== distributed Nat'l Inst

   Senate.STATE.MN.US                      <== state Senate

   House.STATE.MN.US                       <== state House of Reps

   Assembly.STATE.CA.US                    <== state Assembly

Cooper & Postel                                                [Page 39]

RFC 1480                     The US Domain                     June 1993

   MDH.STATE.MN.US                         <== state Health Dept.

   DOT.STATE.MN.US                         <== state Transportation Dept

   CALTRANS.STATE.CA.US                    <== state Transportation Dept

   DMV.STATE.CA.US                         <== state Motor Vehicles Dept

   Culver-City.DMV.STATE.CA.US             <== local office of DMV

   Police.CI.Culver-City.CA.US             <== city department

   Fire-Dept.CI.Los-Angeles.CA.US          <== city department

   Fire-Dept.CO.Los-Angeles.CA.US          <== county department

   Main.Library.CI.Los-Angeles.CA.US       <== city department

   MDR.Library.CO.Los-Angeles.CA.US        <== county department

   Huntington.LIB.CA.US                    <== private library

   SMCC.Santa-Monica.CC.CA.US              <== public community college

   Trade-Tech.Los-Angeles.CC.CA.US         <== public community college

   Valley.Los-Angeles.CC.CA.US             <== public community college

   Hamilton.High.LA-Unified.K12.CA.US      <== public school

   Sherman-Oaks.Elem.LA-Unified.K12.CA.US  <== public school

   John-Muir.Middle.Santa-Monica.K12.CA.US <== public school

   St-Monicas.High.Santa-Monica.CA.US      <== private school

   Crossroads-School.Santa-Monica.CA.US    <== private school

   Mary-Ellens-Montessori-School.LA.CA.US  <== private school

   Progress-Learning-Center.PVT.K12.CA.US  <== private school

   Brick-and-Basket-Institute.TEC.CA.US    <== technical college

   Bunker-Hill.DISTRICT.Los-Angeles.CA.US  <== local district

   SCAQMD.DISTRICT.CA.US                   <== regional district

Cooper & Postel                                                [Page 40]

RFC 1480                     The US Domain                     June 1993

   Berkeley.UC.STATE.CA.US                 <== "CAL"

   Los-Angeles.UC.STATE.CA.US              <== UCLA

   Irvine.UC.STATE.CA.US                   <== UC Irvine

   Northridge.CSU.STATE.CA.US              <== CSUN

   Los-Angeles.CSU.STATE.CA.US             <== Cal State LA

   Leland-Stanford-Jr-University.Stanford.CA.US    <== private school


Cooper & Postel                                                [Page 41]

RFC 1480                     The US Domain                     June 1993


To register a host in the US domain, the US Domain Template must be
sent to the US Domain Registrar (US-Domain@ISI.EDU).  The first few
pages explain each question on the attached template.  FILL OUT THE
TWO PAGE TEMPLATE AT THE END.  Questions may be sent by electronic
mail to the above address, or by phone to Ann Cooper, USC/Information
Sciences Institute, (310) 822-1511.

(1)  Please specify whether this is a new application, modification to
     an existing registration, or deletion.

(2)  The name of the domain.  This is the name that will be used in
     tables and lists associating the domain with the domain server
     addresses. See RFC 1480 - The US Domain for more details.

 <host>.<city/locality>.<state>.US. =  city/locality based names
<school>.<district>.K12.<state>.US. =  kindergarten thru 12th grade
       <school>.PVT.K12.<state>.US. =  private K thru 12th grade
    <school>.<locality>.<state>.US. =  PVT sch opt: locality names
            <school>.CC.<state>.US. =  community colleges
           <school>.TEC.<state>.US. =  technical or vocational schools
         <lib-name>.LIB.<state>.US. =  libraries
       <org-name>.STATE.<state>.US. =  state government agencies
                 <org-name>.FED.US. =  federal government agencies
                 <org-name>.DNI.US. =  distributed national institutes
            <org>.GEN.<state>.US. =  statewide assoc,clubs,domain parks

     For example:

(3)  The name of the entity represented, that is, the organization
     being named.  For example: The Networthy Corporation. Not the
     name of the organization submitting the request.

(4)  Please describe the domain briefly.

     For example: The Networthy Corporation is a consulting
     organization of people working with UNIX and the C language
     in an electronic networking environment.  It sponsors two
     technical conferences annually and distributes a bimonthly

(5)  The date you expect the domain to be fully operational.

Cooper & Postel                                                [Page 42]

RFC 1480                     The US Domain                     June 1993

For every registration, we need both the Administrative and the
Technical contacts of a domain (questions 6 & 7) and we MUST have a
network mailbox for each.  If you have a NIC handle (a unique NIC
database identifier) please enter it.  (If you don't know what a NIC
handle is leave it blank).  Also the title, mailing address, phone
number, organization, and network mailbox.

(6)  The name of the administrative head of the "organization".  The
     administrator is the contact point for administrative and policy
     questions about the domain.  The Domain administrator should work
     closely with the personnel he has designated as the "technical
     contact" for his domain. In this example the Domain Administrator
     would be the Administrator of the Networthy Corporation, not the
     Administrator of the organization running the name server
     (unless it is the same person).

(7)  The name of the technical and zone contact.  The technical and
     zone contact handles the technical aspects of maintaining the
     domain's name server and resolver software, and database files.
     He keeps the name server running. More than likely, this person
     would be the technical contact running the primary name server.


PLEASE READ:  There are several types of registrations.

   (a)  Delegation (i.e., a portion of the US Domain name space is
        given to an organization running name servers to support that
        branch; For example, K12.TX.US, for all K12 schools in Texas).
        For (a) answer questions 8 and 9.

   (b)  Direct Registration of an IP Host.
        For (b) answer question 10.

   (c)  Direct Registration of a non-IP Host.
        For (c) answer question 11 and 12.



(8)  PRIMARY SERVER Information.  It is required to supply both the
     Contact information as well as hardware/software information of
     the primary name server.

(9)* SECONDARY SERVER Information. It is required to supply the
     hardware and software information of all secondary name servers.

Cooper & Postel                                                [Page 43]

RFC 1480                     The US Domain                     June 1993

Domains must provide at least two independent servers that provide the
domain service for translating names to addresses for hosts in this
domain. If you are applying for a domain and a network number
assignment simultaneously and a host on your proposed network will be
used as a server for the domain, you must wait until you receive your
network number assignment and have given the server(s) a net- address
before sending in the domain application. Establishing the servers in
physically separate locations and on different PSNs and/or networks is
strongly recommended.

NOTE: For those applicants not able to run name servers, or for non-IP
hosts the Name Server information is not applicable. (See #10 and #11).
QUESTION FOR DIRECT IP HOSTS (If you answered 8 & 9 do not answer
10, 11, or 12).

(10) What Domain Name System (DNS) Resource Records (RR) and values are
     to be entered for your IP host (must have an "A" record).

     Example: RRs for an INTERNET hosts.

     (a)  DOMAIN NAME (required)...:  Networthy.Santa-Clara.CA.US.
     (b)  IP ADDRESS (required)....:  A  (required)
     (c)  HARDWARE (opt)...........:  SUN-3/11O
     (d)  OPERATING SYS (opt)......:  UNIX
     (e)  WKS (opt)........: UDP (echo tftp) TCP (ftp)
     (f)  MX (opt).................:  10  RELAY.ISI.EDU.

It is your responsibility to see that an IN-ADDR pointer record is
entered in the DNS database.  (For Internet hosts only).  Contact the
administrator of the IP network your host is on to have this done.
The US Domain administration does not administer the network and
cannot make these entries in the DNS database.


   Many applicants have hosts in the UUCP world.  Some are one hop away,
   some two and three hops away from their "Internet Forwarder", this is
   ok.  What is important is getting an Internet host to be your
   forwarder.  If you do not already have an Internet forwarder, there
   are several businesses that provide this service for a fee, (see
   RFC 1359 - Connecting to the Internet What Connecting Institutions
   Should Anticipate, ACM SIGUCCS, August 1992). Sometimes local colleges
   in your area are already on the Internet and may be willing to act
   as an Internet Forwarder.  You would need to work this out with the
   systems administrator.  We cannot make these arrangements for you.

Cooper & Postel                                                [Page 44]

RFC 1480                     The US Domain                     June 1993

(11) Internet Forwarding Host Information

     (11a) What is the name of your Internet forwarding host?
           For example: The host Yacht-Club.MDR.CA.US uses
           UUCP to connect to RELAY.ISI.EDU which is an Internet
           host. (i.e., RELAY.ISI.EDU is the forwarding host).

     (11b) What is the name of your contact person at forwarding host?
           The Administrator of RELAY.ISI.EDU must agree to be the
           forwarding host for Yacht-Club.MDR.CA.US, and the
           forwarding host must know a delivery method and route to
           Networthy.  No double MXing.

     (11c) What is the mailbox of your contact?
           What is the mailbox of the administrator of the forwarding

              Example:  Contact Name......:  John Smith
                        Contact Email.....:  js@RELAY.ISI.EDU

(12) What Domain Name System (DNS) Resource Records (RR) and values
     are to be entered for your NON-IP host.

     Example: RRs for a NON-IP host (uucp).

     (a)  DOMAIN NAME (required).....:   Yacht-Club.MDR.CA.US.
     (b)  HARDWARE (opt).............:   SUN-3/11O
     (c)  OPERATING SYS (opt)........:   UNIX
     (d)  MX (required)..............:   10  RELAY.ISI.EDU.


Cooper & Postel                                                [Page 45]

RFC 1480                     The US Domain                     June 1993

                          US DOMAIN TEMPLATE                    [6/93]

Sections or fields of this form marked with an asterisk (*) may be
copied as many times as necessary. (For example: If you had two phone
numbers for the Administrative Contact, you would use the same number
           (N)ew (M)odify (D)elete..:


      3a.  Organization Name.....:
      3b.  Address Line 1........:
      3b.  Address Line 2........:
      3c.  City..................:
      3d.  State.................:
      3e.  Zip/Code..............:


      5.   Date Operational......:

      6a.  NIChandle (if known)..:
      6b.  Whole Name............:
      6c.  Organization Name.....:
      6d.  Address Line 1........:
      6d.  Address Line 2........:
      6e.  City..................:
      6f.  State.................:
      6g.  Zip/Code..............:
      6h.* Voice Phone...........:
      6i.* Electronic Mailbox....:

      7a.  NIChandle (if known)..:
      7b.  Whole Name............:
      7c.  Organization Name.....:
      7d.  Address Line 1........:
      7d.  Address Line 2........:
      7e.  City..................:
      7f.  State.................:
      7g.  Zip/Code..............:
      7h.* Voice Phone...........:
      7i.* Electronic Mailbox....:

Cooper & Postel                                                [Page 46]

RFC 1480                     The US Domain                     June 1993

organizations running name servers for a branch of the US Domain
name space, for example:  k12.<state>.us).

      8a.  NIChandle (if known)..:
      8b.  Whole Name............:
      8c.  Organization Name.....:
      8d.  Address Line 1........:
      8d.  Address Line 2........:
      8e.  City..................:
      8f.  State.................:
      8g.  Zip/Code..............:
      8h.* Voice Phone...........:
      8i.* Electronic Mailbox....:
      8j.  Hostname..............:
      8k.* IP Address............:
      8l.* HARDWARE..............:
      8m.* OPERATING SYS.........:

      9a.* Hostname..............:
      9b.* IP Address............:
      9c.* HARDWARE..............:
      9d.* OPERATING SYS.........:


     10a.  DOMAIN NAME...........:
     10b.* IP ADDRESS (required).:
     10c.  HARDWARE..............:
     10d.  OPERATING SYS.........:
     10e.  WKS ..................:
     10f.* MX....................:


     11a.  Forwarding Host......:
     11b.  Contact Name.........:
     11c.  Contact Email........:

     12a.  DOMAIN NAME...........:
     12b.  HARDWARE..............:
     12c.  OPERATING SYS.........:
     12d.* MX (required).........:

Cooper & Postel                                                [Page 47]