mostly adding some documentation bits

2026-02-03 17:24:27 -07:00
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+# TEMPORARY NOTES
+
+(to be moved elsewhere)
+
+## Amsterdam Identifier Values
+
+Amsterdam identifier values are used for user names, community aliases, and conference aliases, and may be used
+for other purposes in the future. A valid Amsterdam ID consists of characters from the following character set:
+
+* Alphanumerics (A-Z, a-z, 0-9)
+* Dash (-)
+* Underscore (_)
+* Tilde (~)
+* Asterisk (*)
+* Apostrophe (')
+* Dollar sign ($)
+
+All characters are represented in the ISO 8859-1 character set, and may be represented with single-byte encoding
+in UTF-8.  Also note that all Amsterdam identifiers are case-insensitive.
+
+### Rationale
+
+The character set was defined starting with the list of characters allowable in URL path components ("pchar" as
+defined in [RFC 3986](https://www.rfc-editor.org/rfc/rfc3986.txt), section 3.3, page 23), minus the percent-encoded
+forms, so that Amsterdam identifiers would be usable as "path information" in a URL.
+
+The ampersand (&) was excluded because of its possible confusion with a URL parameter separator, and because it requires HTML escaping.
+
+The at sign (@) was excluded because of possible confusion with E-mail addresses and XMPP identifiers.
+
+The plus sign (+) was excluded because of possible confusion with a URL=encoded space character.
+
+The comma (,) was excluded because of its possible interpretation as a separator character.
+
+The equals sign (=) was excluded because of its possible confusion with a URL parameter/value separator.
+
+The semicolon (;) was excluded because of its possible interpretation as a separator character.
+
+The colon (:) was withheld to provide for a possible future "namespace" expansion (as in XML namespaces).
+
+The parentheses ((, )) were excluded because of possible confusion with user link syntax in conferencing.
+
+The period (.) was excluded because of possible confusion with post link syntax in conferencing.
+
+The exclamation point (!) was excluded because of possible confusion with extended post link syntax in conferencing.
+
+The definition of Amsterdam identifiers was taken almost directly from the definition of Venice identifiers in the predecessor project.