Oh, yes, there are absolutely counter-examples. It's essentially down to each WG whether they issue errata or revised recommendations, and when plenty of (admit

Oh, yes, there are absolutely counter-examples. It's essentially down to each WG whether they issue errata or revised recommendations, and when plenty of (admittedly more obscure) WGs have their charter allowed to expire when all of their deliverables have become recommendations there's at times nobody to maintain the document per the W3C process. An aside: XML 1.0 Fifth Edition is actually a weird case: there are documents that are well-formed XML according to the Fifth Edition and not well-formed according to the Fourth Edition, because the characters allowed in places like tag names went from being based on Unicode 2.0 to Unicode 5.0-or-any-later-version (which was originally the difference between XML 1.0 and XML 1.1, except 1.1 was originally 3.0-or-any-later-version); as such, two XML 1.0 implementations are no longer guaranteed to consider the same set of documents well-formed, as it depends on the Unicode version each uses. As a result, plenty of implementations of XML 1.0 have no plan on changing away from their Forth Edition implementations.