[Insipid] Use of Session-ID in 100 (Trying) response

"DRAGE, Keith (Keith)" <keith.drage@alcatel-lucent.com> Thu, 26 March 2015 21:17 UTC

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From: "DRAGE, Keith (Keith)" <keith.drage@alcatel-lucent.com>
To: "insipid@ietf.org" <insipid@ietf.org>
Thread-Topic: Use of Session-ID in 100 (Trying) response
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Date: Thu, 26 Mar 2015 21:17:01 +0000
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Subject: [Insipid] Use of Session-ID in 100 (Trying) response
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I was a little surprised to see the Session-ID header field appearing in 100 (Trying). In general 100 (Trying) is hop by hop, with a very specific purpose of telling the preceding entity to turn of timers, and most header fields never appear in 100 (Trying). Therefore I would have expected this one to be absent as well.

Can anyone elaborate on why the current inclusion is in the draft?