"As a MediaWiki Developer, I want to get, set and delete the 'regular' HTML output in the parser cache, so that it's easy to get the 'regular' HTML, no matter how that's generated."

As we change over from 'old' HTML to the new Parsoid HTML, we don't want every single cache access to need to change. There should be a way to get the 'default', 'normal', 'unspecified' or 'regular' HTML format, where in this case 'default' means the format that is output in the Web UI for pages, and for UI strings. (If those are different, page-output wins).