Errata: the flag is `dom.lift_select_parser_restrictions.enabled`, not `dom.element.popoverhint.enabled` as I accidentally copy/pasted in OP
On Tue, 19 May 2026, at 3:04 PM, Keith Cirkel wrote: > Summary: Support for additional elements inside the select element. > Bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1933591 > Specification: https://github.com/whatwg/html/pull/10557 > Standards Body: WHATWG > Platform coverage: All > Preference: dom.element.popoverhint.enabled > Devtools bug: N/A > Other browsers: > - Blink: Shipping around M135. > - WebKit: Shipping in Safari TP 242 > (https://webkit.org/blog/17934/release-notes-for-safari-technology-preview-242/). > web-platform-tests: > https://wpt.fyi/results/html/semantics/forms/the-select-element/customizable-select/select-parsing.html?label=experimental&label=master&aligned > > As part of "customizable select", all browsers have needed to make changes to > the HTML parser in order to drop special modes around parsing `<select>` > elements and its children. We've had this behaviour _flagged_ in nightly for > a release cycle. > > I've landed https://phabricator.services.mozilla.com/D295502 as part of the > 153 train, which enables the new parser modes by default. This is a > prerequisite for supporting new elements such as `<selectedcontent>` inside > of `<select>`, as well as the new `appearance:base` mode for `<select>`. I'll > be following up by cleaning up the feature flag. > > As usual, if any issues arise, please let the DOM team know and we can roll > this back. We do not anticipate issues given the 152 nightly cycle had this > unflagged, but this means that from 153 this will be on in release channels. > > If anyone has any concerns please let me know! > > Happy browsing. -- You received this message because you are subscribed to the Google Groups "[email protected]" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/a/mozilla.org/d/msgid/dev-platform/6ea8edce-912d-4ecd-a8ab-1344dd9e3e6f%40app.fastmail.com.
