Per the parent task, we need a syntax like <translate nowrap>...</translate> to prevent wrapping in places where it would break things.
Affected documentation
QA plan
Affected projects: All Wikimedia projects using Translate
Pre (or post)-deployment testing: Try marking translatable pages with regular and new nowrap sections. Translate them, update source to make them fuzzy. Check translation pages that nowrap sections are not marked as outdated, but regular sections are. This will be easier to test when other tasks of the parent tasks are resolved, because then untranslated sections are wrapped too.
Outcome
New syntax <translate nowrap>...</translate> can be used on translatable pages to prevent wrapping of section text inside html tags. Currently this only affects marking of outdated sections, but in future it will also affect any other kind of wrapping.