Re: Proposal for updated SF format for No-Vary-Search params

Am 16.01.2026 um 09:14 schrieb Nidhi Jaju:
> Hi HTTP Working Group,
> 
> As a result of some feedback from Working Group Last Call for the No- 
> Vary-Search document (https://datatracker.ietf.org/doc/draft-ietf- 
> httpbis-no-vary-search/ <https://datatracker.ietf.org/doc/draft-ietf- 
> httpbis-no-vary-search/>), we have a new proposal to update the 
> structured field format for the `params` field in the No-Vary-Search header.
> 
> The proposal is essentially to update the `params` field to be an inner 
> list of strings, and only allow for it to be present when `except` is 
> not present. This allows us to simplify the algorithm, but based on 
> https://chromestatus.com/metrics/feature/timeline/popularity/4425 
> <https://chromestatus.com/metrics/feature/timeline/ 
> popularity/4425>, potentially breaks interoperability for those that 
> have already deployed the current draft's syntax in production. From the 
> perspective of one implementation, if we were to merge this change, 
> Chrome's plan is to support both syntaxes for a short time before 
> deprecating the older syntax.
> 
> Please take a look at https://github.com/httpwg/http-extensions/ 
> pull/3374 <https://github.com/httpwg/http-extensions/pull/3374> for the 
> full proposed change, and we would appreciate it if you could respond 
> with any comments or concerns.
> 
> Thank you!
> 
> Best,
> Nidhi obo the authors

Needless to say, as I made that proposal, I'm in favor.

I appreciate Chromium's statement that they can migrate to the new format.

Best regards, Julian

Received on Friday, 23 January 2026 09:25:51 UTC