Standardization of host call letters
Four-letter nicknames for early ARPANET computers
Bhushan, A. and R. Metcalfe, "Standardization of host call letters", RFC 233, DOI 10.17487/RFC0233, September 1971, <https://www.rfc-editor.org/info/rfc233>.
@misc{rfc233,
series = {Request for Comments},
number = 233,
howpublished = {RFC 233},
publisher = {RFC Editor},
doi = {10.17487/RFC0233},
url = {https://www.rfc-editor.org/info/rfc233},
author = {A. Bhushan and R. Metcalfe},
title = {{Standardization of host call letters}},
pagetotal = 2,
year = 1971,
month = sep,
} RFC text
Network Working Group 28 Sept 71 Abhay Bhushan
RFC #233, NIC #7650 Bob Metcalfe
Standardization of Host Call Letters
------------------------------------
We agree with Peggy Karp (See RFC #226) that there would be some
benefit in standardizing the symbolic host names used in TELNET
programs. It should be recognized that there is a trade-off
between brevity and mnemonicism. It is our feeling that a good
set of host call letters can be developed using only four
characters (see Jim White's in RFC #206.) Each host should
suggest its own call letters. Upper and lower case letters
should be used interchangeably. The following is our currently
recommended list:
Host Number Name-4 Name-8
----------- ------ ------
1 sex sex-ucla
65 ccn ccn-ucla
2 nic nic-sri
66 srai sri-ai
3 ucsb ucsb
4 utah utah
5 bbn5 bbn-516
69 bbna bbn-10x
133 bbnb bbn-x10x
6 mult multics
70 dmcg mit-dmcg
134 its mit-ai
7 ra65 rand-65
71 ra10 rand-10
8 sdc sdc
9 harv harvard
73 har1 harvpdp1
137 ha11 harpdp11
10 ll67 linc-67
74 tx2 linc-tx2
11 stan stanford
12 ill illinois
13 case case
14 cmu cmu
15 paol paoli
16 ames ames-67
144 amtp ames-tip
145 mttp mitretip
18 radc radc
146 rdtp radc-tip
19 nbs nbspdp11
147 nbtp nbs-tip
148 etac etac
21 tink tink-418
22 mccl mccl-418
23 usc usc-44
151 ustp usc-tip
152 gwc gwc-tip
25 ncar ncar7600
153 nctp ncar-tip
158 bbtp bbn-tip
[ This RFC was put into machine readable form for entry ]
[ into the online RFC archives by BBN Corp. under the ]
[ direction of Alex McKenzie. 12/96 ]
AI ELI5
On this page
§1The Need for Standard Host Names
The ARPANET of 1971 had multiple computers at different sites. Telnet users had to know which host to connect to, but there was no standard way to refer to them. Different programs and different sites used different names or numbers. This RFC proposes standardizing on call letters using four characters, with eight-character names as alternatives.
The authors note that brevity and memorability are both valuable: a short code is easy to type, but a longer mnemonic is easier to remember. Their proposal balances both by offering both lengths.
Each computer needs a short name people can type and remember, like how radio stations have call signs.
§2The Proposed Naming Scheme
Each host number gets two names: a four-character short form and an eight-character long form. Upper and lower case are treated as equivalent, so typing is flexible. The RFC publishes a table of about 40 hosts with their proposed names, such as SEX for host 1 (UCLA), NIC for host 2 (SRI), and UTAH for host 4.
The authors recommend that each host organization should propose its own preferred call letters rather than having them imposed. This lets sites choose names that make sense in their own context.
Each computer gets a short four-letter name and a longer eight-letter option, and the people running each computer can choose what they want to be called.
§3Implementation and Adoption
The RFC notes that Telnet programs would use these call letters to let users type a simple name instead of a numeric address. Case-insensitive matching means a user could type sex, SEX, or Sex and reach the same host.
The proposal is straightforward: maintain a shared list of call letters, ensure all Telnet implementations recognize them, and let network sites update the list as new hosts join the network.
Once everyone agrees on the names, Telnet programs can look them up so a user just types the name instead of a number.