So I was wondering for ages how we could search for Super Mario Maker courses by name when we don't know who made it nor the course ID, but with the SMM Bookmark site and Google, I didn't realize how simple it actually was until I read about it at https://www.reddit.com/r/MarioMaker/comments/43962s/how_to_search_by_name_not_within_the_game/czgtesm
So for example, if you want to find a Rainbow Road level, then in Google search you just type this:
site:supermariomakerbookmark.nintendo.net/courses "rainbow road"
And it will return all Rainbow Road courses.
Hopefully this can be handy for some people :)