Hello all,

We'd like to inform you of a change coming in how media is structured in the parser's HTML output. It has been [in the works for quite some time][1]. The new structure was prototyped in Parsoid's output since its inception and outlined in [its specification][2].

The proposed change has gone through the [RFC process][3] and an implementation to output this new structure in MediaWiki's core parser was [recently merged][4], gated behind a flag. So far, it has been enabled on testwiki and testwiki2.

There are [a number of known issues][5] but we don't expect to see many rendering differences since we've done some [extensive visual diff testing][6]. Templates won't be impacted; the old CSS styles will remain, for now.

However, where we do expect work is needed is with code interacting with the page, be it user scripts, gadgets, extensions, bots, or other things.

If you'd like to help us out and get ahead of the changes before they have the potential to interfere with your workflow, please visit these wikis and test them out. You can file tasks in Phabricator with the Parsoid-Media-Structure project tag.

Thanks, The Parsing Team

[1]: https://www.mediawiki.org/wiki/Parsing/Media_structure [2]: https://www.mediawiki.org/wiki/Specs/HTML/2.2.0#Media [3]: https://phabricator.wikimedia.org/T118517 [4]: https://gerrit.wikimedia.org/r/c/mediawiki/core/+/507512 [5]: https://phabricator.wikimedia.org/project/board/5428/ [6]: https://phabricator.wikimedia.org/T266149