DNT Extension syntax unclear; exclude apostrophe?

[r12a]

5.2.1 Extensions to the DNT Field Value
https://w3c.github.io/dnt/drafts/CRc-tracking-dnt.html#dnt-extensions

 DNT-extension   = %x21 / %x23-2B / %x2D-5B / %x5D-7E
                ; excludes CTL, SP, DQUOTE, comma, backslash

This is a minor editorial nit. The names for the characters in the "excludes" comment are not the Unicode names nor are they particularly clear. CTL appears to refer to all control characters. SP would be clearer as SPACE, DQUOTE as double-quote. comma and backslash are fine.

I would have expected apostrophe to be on the excluded list as well, since it has meaning in JSON?

[r12a]

NOTE: Some responses have already been made to this comment. See w3c/i18n-activity#508. Please continue the discussion here.

[royfielding]

DNT-extensions is the ABNF for what octets are allowed as extensions to the DNT field-value, which is an HTTP header field in US-ASCII. There is no expectation of natural language. The all-caps names in that comment are ABNF syntax rules known to anyone implementing HTTP.

https://tools.ietf.org/html/rfc5234#page-13

and in any case are just comments to explain what isn't included in the normative range of octets.

[aphillips]

As part of regular housekeeping, the I18N WG is removing our tracking label and closing this issue.