Need consistent normative language for txn claim

[PieterKas]

WGLC feedback from Dan Moore

I'm confused about the txn claim
https://www.ietf.org/archive/id/draft-ietf-oauth-transaction-tokens-06.html#section-7.3-6 says it MUST be set.
https://www.ietf.org/archive/id/draft-ietf-oauth-transaction-tokens-06.html#name-identifying-call-chains says setting it is RECOMMENDED.
which is correct or am I missing some context?

[PieterKas]

https://www.ietf.org/archive/id/draft-ietf-oauth-transaction-tokens-06.html#section-7.3-6 says it MUST be set.

https://www.ietf.org/archive/id/draft-ietf-oauth-transaction-tokens-06.html#name-identifying-call-chains RECOMMENDS that it should be unique. The reasons for not mandating uniqueness is because of the challenges of ensuring that at scale - it is a best effort.

My recommendation is to make not changes:

@tulshi @gffletch - thoughts?