When a moderator closes a thread in UMS Assistance they would 'tag' the thread with categories the thread answers questions about. We could then search for those categories, and only get results where the problem was solved. Generally, this would mean we could find correct answers to problems related to the category we are interested in, and each category could even correspond with a wiki article condensing the knowledge with a link at the bottom to a search for posts of said category. Of course, this would all only apply to threads closed due to an acceptable solution being presented, and not those closed due to rule violations.
For example, all the posts relating to grids that were solved would be tagged with grid, along with any other categories they end up covering. I could then search within category grid for 'freezes', and get only results for 'freezes' that are solved threads related to grids.
I imagine this feature would be more useful for those that have more experience in making maps, as they would better be able to determine the nature of their problem/question. Also, should the above be implemented, it'd be nice if we could also exclude categories from our search.
None.