MediaWiki parser uses the strip markers (\127UNIQ--tagname-8 hex digits-QINU\127 strings) internally for certain operations while processing the input. They aren't supposed to appear in the output, but sometimes they do. Here the different issues of this kind are tracked.
UNIQ/QINU tends to be shown when there is either a broken or invalid template call on a page. It is sometimes also displayed if an extension tag has a bug in its PHP code where it processes some of the wikitext only partially.