Re: [Cbor] Tagging requirement

[Carsten Bormann <[e-mail]>]

On 2020-08-17, at 19:56, Laurence Lundblade <[e-mail]> wrote:
> 
> At this point the word “tag” is confusing to me.  When you say “use Tag 1” you seem to mean encode a type 6 integer

(The argument is not used as an integer, but as a tag number.)

> with value 1 followed by the content which is a number.

Yes.

> Unless explicitly allowed, the type 6 integer and number content are inseparable. 

As long as you are talking about Tags, yes: Tags are a major-type 6 container.
You can also borrow the definition of a Tag content data structure for an application protocol, but then you aren’t using a Tag, you are using the definition of a Tag content data structure (or “an unwrapped tag”, if you must say so).

> When you say USE tag 1, it means both the type 6 integer and the number content. By contrast, when CWT refers to the “CWT tag” it is just referring to the type 6 integer.

We recently revisited that terminology in 7049bis; this is a bit similar (but inverse) to what are tags and elements in XML — what are called elements in XML (except by the 95 % who don’t know the difference between a tag and an element) are tags in CBOR, and what are tags in XML are not really discussed very much (they are briefly referred to as “heads”).

Grüße, Carsten