[OASIS Issue Tracker] Commented: (MQTT-24) Edits to Introduction section

[OASIS Issues Tracker <workgroup_mailer@lists.oasis-open.org>]

    [ http://tools.oasis-open.org/issues/browse/MQTT-24?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=33849#action_33849 ] 

Raphael Cohen commented on MQTT-24:
-----------------------------------

How about Unicode 6.2.0: http://www.unicode.org/versions/Unicode6.2.0/

This will give us several years of just not having to worry about change, and the very best support for East Asian and other scripts.

We should also make a simple statement that UTF-8 encodings MUST NOT have a three character initial BOM. (Which is meaningless, and useless in MQTT context, but I have seen people do this inside other protocols). Likewise, a clarification that the encoding MUST NOT be Java's Modified UTF-8, and can contain ASCII NUl. (All are obviously to most people, but being explicit is good).

At the same time, it's probably worth nothing too that certain unicode combinations are invalid in UTF- 8 - the use of surrogate pairs from UTF-16 re-encoded and certain non-transmissable characters (eg U+FFFE from memory) - these normally delimit the last 2 characters in a multi-lingual plain. These restrictions are only a minor burden fro java implementations using the naive methods in string / character. These restrictions serve to stop propagation of bad data through a network of nodes.

I'll leave it as an open question if we want to add 'implementations MAY decide to not support the use of ASCII NUL and C0 / C1 control codes' / MAY decide to place additional restrictions on supported characters. (Typically, this is to do with automatic logging in environments where such codes can be used as escape sequence attacks, etc).


> Edits to Introduction section
> -----------------------------
>
>                 Key: MQTT-24
>                 URL: http://tools.oasis-open.org/issues/browse/MQTT-24
>             Project: OASIS Message Queuing Telemetry Transport (MQTT) TC
>          Issue Type: Improvement
>          Components: edits
>    Affects Versions: 3.1.1
>            Reporter: Peter Niblett
>            Priority: Minor
>
> 1. The introduction says the spec has three main sections, however there's now an additional section on Conformance requirements.
> 2. The Normative References should include a reference to a Unicode standard, as well as to UTF-8.

-- 
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators: http://tools.oasis-open.org/issues/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira