This is a tracking task for my work In support of T133711: Question mark in query causes it to turn up unrelated search results
We (the search team) created a page on meta wiki describing in detail the situation regarding search queries that end in question marks.
We sent an invite out to a few of the top wikipedias (Those that our incredible volunteer translations were able to help with) on their Village Pumps.
A post to the public discovery and wikitech-l mailing list was sent on 7 July 2016:
https://lists.wikimedia.org/pipermail/discovery/2016-July/001183.html
https://lists.wikimedia.org/pipermail/wikitech-l/2016-July/086003.html