Touching a Wiki page.. making a small grammatical or formatting correction in order to pop it onto RecentChanges and possibly influence thought on pages that are currently being developed.
Another, less subtle method is to add a link from one of the pages to the other. This is more permanent, and LinksAreContent, but much more blatant and possibly not what's wanted. On the other hand, a WikiFeint would only last a couple of days, and may never be noticed (too subtle?). Surely, for the long-term health of Wiki, a link is a much better solution. Perhaps a WikiFeint would be appropriate on topics where being explicit could damage your argument, but that's not what Wiki's about anyway.
Useful both in exposing the WikiIceberg and in OrphanPages triage.