From what I've seen, the search feature here uses words in the description. I keep running into trouble remembering the exact name of categories. As we get more and more categories, creators will need to better think about words that should be used in the description. Maybe adding a category creator keyword at the end of the description would help.
Some examples of failed searches that really shouldn't have failed:
I searched for scuba (when I was looking for a scuba shop) and the one thing that showed up was "Dive Sites". Dive shops should also have shown up but without scuba in description, no luck.
Keyword "animal" gives you 50 responses but not "Bear Statues".
"ben" gives you nothing, not even "Benjamin Franklin".
Have you searched for other categories that you know are there but couldn't find them by the keyword you thought should bring them up? If so, add them to this thread, maybe they will get added.