RFC 615

Proposed Network Standard Data Pathname syntax

📅 published March 1974, from ietf

RFC 615, Proposed Network Standard Data Pathname Syntax 🎀

Network Working Group · D. Crocker (UCLA-NMC) · MAR 74 · NIC #21531 ✨

The header doesn't list anything it obsoletes or updates, so there's no drama there. 💅 This one is a proposal, so it's basically D. Crocker floating an idea and asking everyone to weigh in. 🦋

The Big Idea 💖

okay so there's been an increasing call for a Network Standard Data Pathname (NSDP). Basically a standard way to point at a specific spot where a collection of bits lives somewhere on the Network. 🌸

The reasons for a standard (or virtual anything) have been talked about at length elsewhere, so I'm not going to rehash them here. 🙈 Instead, the author only wants to propose a standardized SYNTAX for writing pathnames. This is useful for three groups of people:

users who don't know a site well, or who use lots of different sites and don't want to memorize each site's quirks 🧚
programs that access data at several other sites 🤖
documentation 📚

The syntax lets you specify the network, host, peripheral device, directory, file, type, and site-specific fields. Adding more fields later is expected to be quite simple. ✨

The BNF 🍓

Here's the grammar, bestie. 🫶

   <NSDP> ::= % <bulk> <cr><lf>

   <bulk> ::= <field> / <field> <bulk>

   <field> ::= <key> <L-delim> <name> <R-delim>

   <key> ::= NETWORK / HOST / PERIPHERAL/ DIRECTORY /
             FILE / TYPE / SITEPARM / N / H / P / D / F /
             T / S

<L-delim> ::= any printable character that is not in the
              succeeding <name> field and that is
              acceptable to the object site: For visual
              aesthetics and to facilitate human parsing,
              anytime <L-delim> is a left-bracket
              character (<, [, (, _), <R-delim> must be
              the complementary right-bracket character
              (>, ], ), |).

<name> ::=    any sequence of characters acceptable to the
              object site. This is the actual data field
              with the file, directory, device (or
              whatever) name.

<R-delim> ::= Either 1) the same character as <L-delim> or
              2) if the <L-delim> character is a
              left-bracket character (<, [, (, _) then its
              complementary right-bracket (>, ], ), |).

<cr> ::=      carriage-return

<lf> ::=      line-feed

More Details, Please 🔥

The syntax lets <name> fields be an arbitrary number of rs long. 🤷‍♀️ Case doesn't matter to the syntax itself, though some sites will care about case inside <name> fields. 💅

<key> tells you what part of the pathname the next <name> is going to refer to. The single-character keys are just abbreviations for the full-word keys. 🦋

The <field>s are order dependent, but defaulted ones can be left out. The order is the one shown for <key>s, so: Network, Host, ..: Siteparm. 👑

Fields can be repeated when the object site is fine with it, so you can have multiple Directory fields and so on. 🌈

Whether a combination of <field>s is valid is totally up to the site. For example, if a site will accept it, an NSDP with a Host field and nothing else is allowed. 💀

<delim> is used to mark the beginning and end of the <name> field. ✨

Explaining the Keys 🧚

       NETWORK or N:   Currently, only ARPA is defined.

       HOST or H:      Reference to host, by official name or
                       nickname or number: The default radix is
                       ten; a numeric string ending with "H"
                       indicates hexadecimal, "O"(oh) indicates
                       octal, and (gratuitously) "D" indicates
                       decimal:

      PERIPHERAL or P: Peripheral device being referred to:

      DIRECTORY or D:  Name of a directory which contains a
                       pointer to the entity (directory or
                       filename) specified in the following
                       <field>:

      FILE or F:       Basic name of the file or data set:

      TYPE or T:       Optional modifier to filename: (Tenex
                       calls it the extension.)

      SITEPARM or S:   A parameter, such as an access
                       specification or version number, peculiar
                       to the object site. The content of the
                       <name> field must serve to identify what
                       Siteparm is involved. Each site will be
                       responsible for defining the syntax of
                       Siteparm <name>s it will accept.

Reserved PERIPHERAL Names 🍓

These are the reserved peripheral <name>s. Stan-worthy list, honestly. 🫶

      DISK or DSK:     Immediately accessible, direct-access
                       storage.

      ONLINE or ONL:    Whatever immediately-accessible (measured
                        in fractions of a second) storage the
                        user accesses by default; usually disk:

      TAPE or TAP:      Industry-compatible magnetic tape:

      TAPE7 or TP7:     7-Track industry compatible tape:

      TAPE9 or TP9:     9-Track industry compatible tape:

      DECTAPE or DEC:   DEC Tape.

      OFFLINE or OFF:   Any tertiary storage; usually tape,
                        though "devices" like the Datacomputer
                        are permissible: The user should expect
                        to wait minutes or hours before being
                        able to access OFFLINE files:

      PRINTER or PTR:   Any available line-printer:

      DOCPRINTER or DOC:Upper-lower case line printer, preferably
                        with 8 1/2" X 11" unlined paper.

      PAPER or PAP:     Paper tape.

      PUNCH or PUN:     Standard 8O-column card punch.

      READER or RDR:    Standard 80-column card reader:

      OPERATOR or OPR:  System Operator's console.

      CONSULTANT or CON: On-line consultant.

Defaults 🌸

Defaults are usually context dependent, so the author offers these as guidelines only 💅:

      Network:    ARPA

      Host:       The host interpreting the NVP

      Peripheral: ONLINE (DISK)

      Directory:  The user's current "working" directory,
                  usually set by the logon process:

      Filename:    None.

      Type:        None.

      Siteparm:     None.

General Comments 💜

The only field that has to be checked against any host's current syntax is the escape-to-NVP field (the per-cent sign as the first character of a pathname specification). It isn't currently known to conflict with any host's syntax. 🔥

The exclamation mark (!) is the only other character that seems permissible, assuming it should be a graphic. Using it would cause minor problems at Multics. But more importantly, as a graphic it's too similar to the numeral "1". 🙈

The syntax is meant to be adequate for all hosts, so any given part of it might be inappropriate for a given host. 🧚

A site is expected to permit specifications in a given field if and only if that site already has a way of accepting the same information. 👑

The author believes any changes to the syntax will be graceful additions rather than a wholesale redesign, so they can be put off for a while. For now, any undefined attributes must be specified in a Siteparm field. ✨

Version, Access protection, and Accounting, plus other kinds of info, might be better as standard <key>s instead of being buried as Siteparms. The author expects the next version of the NSDP Syntax specification to include them as <key>s, but wants to wait for community comments first. 🦋

The syntax doesn't currently allow addressing any collection of bits smaller than a file. This could be fixed by adding PAGE, BYTE, and other <key>s, but again, the author would like to collect some comments first. 🌈

Disclaimer 🙈

A pathname written in the proposed syntax is pretty easy to type but kinda ugly to read. So, at the cost of design cleanliness, the <L-delim>/<R-delim> syntax was modified to try to fix this somewhat. As you'll see below, it's only partially successful. 💀

The first draft used a mix of Tenex and Multics conventions, like this: (Network)[Host]Peripheral:Directory>Filename:Type;Siteparm It looked nicer and was generally quicker to type, but it lacks extensibility. For example, adding Version number or Access protection as standard fields would be difficult. 😭

It's suggested that human interfaces be built to translate to and from NSDP syntax and the user's standard environment. 🫶

Sample Pathnames 🎀

Here are some examples, iykyk. 🧚

%H[ISI]D<DCROCKER>F(MESSAGE)T/TXT/S(P77O4O4)<cr><lf>

This refers to my protected message file at ISI (<DCROCKER>MESSAGE:TXT;P77O4O4). 🔥

%H/OFFICE-l/D>JOURNAL>F<l8659>T.NLS.<cr><lf>

This refers to NIC Journal document #18659 (Tenex file <JOURNAL>l8659:NLS). 📚

%H/65/D.ARP061.D.LAD:F.DOCUMENT.<cr><lf>

This refers to a file ARPO6l:LAD.DOCUMENT at UCLA-CCN. Notice the use of multiple Directory fields! 🌈

%H[540]D//D>udd>D>Comp=net>D>Map>F(Mail)<cr><lf>

This refers to the file CompNet>Map>Mail at Mit-Multics. Note that the initial NSPD Directory <name> field is empty. That's how Multics likes to start at the top of its directory structure. 👑

Thank Yous 💖

Big thanks to Jon Postel, Vint Cerf, Jim White, Charlie Kline, Ken Pogran, Jerry Burchfiel, and Tom Boynton for their suggestions. You're all iconic. 🫶✨

📦 where this page comes from

ietf: rfc615 1974-03
💖 girlified by claude-haiku-5-5 on 2026-10-17: a language model's rewrite of the original, under its terms