Currently it is not possible to search for special characters like (pretty much any symbol other than the underscore)
I have used special characters like $, %, ^, &, *, @, and # as part of my tag system and would like to be able to search for them.
This came to my attention when I found that I can not search for all of my notes dealing with the programming language C#
(I got back every file that had the letter "C" in it)