[MMUSIC] QUERY: info about a=cat, a=keywds, a=tool

Paul Kyzivat <pkyzivat@alum.mit.edu> Tue, 05 August 2014 15:48 UTC

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Date: Tue, 05 Aug 2014 11:48:26 -0400
From: Paul Kyzivat <pkyzivat@alum.mit.edu>
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Subject: [MMUSIC] QUERY: info about a=cat, a=keywds, a=tool
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I volunteered to draft ABNF syntax for the attributes defined in RFC4566 

There are some that I have very little information about:

    a=tool:<name and version of tool>

They have all been in SDP since RFC2327 in 1998. And I don't think I 
have ever seen any of them used. I did a google search over ietf.org 
looking for usages without luck. And they are all very vague about their 

The safe answer is to just define the value syntax for each of then as 
<byte-string>. But at least for a=cat the value (category) is specified 
as "dot-separated hierarchical category", so it seems reasonable that 
the syntax ought to involve dots in some way.

Perhaps these should all be deprecated.

Is there anybody still here who remembers when these were defined, and 
what the expectations were about the syntax?