Re: [Cbor] 7049bis: The concept of "optional tagging" is not really used in practice #126

Carsten Bormann <cabo@tzi.org> Wed, 23 October 2019 13:04 UTC

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From: Carsten Bormann <cabo@tzi.org>
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Subject: Re: [Cbor] 7049bis: The concept of "optional tagging" is not really used in practice #126
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… and I dropped a PR addressing this and other remaining tag issues (#107).

https://github.com/cbor-wg/CBORbis/pull/127

I hope there is still some time for reading this before 1500Z…

Grüße, Carsten


> On Oct 23, 2019, at 13:38, Carsten Bormann <cabo@tzi.org>; wrote:
> 
> Section 3.4 talks about "optional tagging" as a secondary purpose of tags. But in today's CBOR protocols, tags are rarely "optional" in the sense that they can simply be left out without a change in semantics, as 3.4 para 3 implies.
> 
> This concept comes up again in 4.2.2, where "optional tagging" is outlawed in deterministic encoding (but then the text goes on to explain that protocols might choose to retain tags, but doesn't say why).
> 
> Proposal: Get rid of any discussion of “optional tagging". 
> (Of course, understanding/processing tags remains an optional feature of a decoder.)
> 
> https://github.com/cbor-wg/CBORbis/issues/126
> 
> Grüße, Carsten
> 
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