Re: [csswg-drafts] Versioning policy and backwards incompatible changes (#5114)

> We also have a long term ambition to fully obsolete CSS2, which will then lead to the question as to where the normative definition of Level 2 will live.

I don't think we *will* have a normative definition of Level 2 at that point. It'll be obsoleted just as much as CSS 1 is.  We're not far from that point already.

> At the moment if we make a backwards incompatible change to Level 4, our practice is to make behaviour undefined/optional in L2 and L3 (and ignore L1),

I don't think that's our practice, either?

CSS2 had a lot of stuff declared undefined near the end of its process, not because of backwards-incompatible changes in the level 3 module, but because the behavior wasn't yet consistent between browsers and so we couldn't get 2+ passes for tests for any reasonable defined behavior.

Since then, I don't think we've gone back and undefined things because of a change in later versions, have we? We sometimes remove things because we prefer the levels to not *contradict* each other, just for confusion-avoidance reasons, but there's no sense in which an earlier level is a meaningful artifact which an implementor can decide to support vs a later level. They're just previous versions of the current document, is all.

GitHub Notification of comment by tabatkins
Please view or discuss this issue at using your GitHub account

Received on Tuesday, 26 May 2020 21:27:50 UTC