I made a minor edit to a translated page on mediawiki.org and ran into
Multiple translation unit markers for one translation unit.
Translation unit text:
(wiki markup)
This message is incomprehensible to even an above-average wiki editor. It would help if messages like this could link to wiki documentation explaining "Translation unit", like [[mw:Special:MyLanguage:Extension:Translate/Good_subpage#sAppropriate_section]].