In preparation for T152540, we should remove old code related to $wgExperimentalHtmlIds. This global variable has been turned off for all Wikimedia projects since 2011. The only code we should leave for now is the variable initialization in DefaultSettings.php, which should be marked as deprecated. We should also mark the variable as deprecated at https://www.mediawiki.org/wiki/Manual:$wgExperimentalHtmlIds.
Places this variable is mentioned or used:
- lib/wt2html/tt/Sanitizer.js in parsoid