I created a file titled Foobar 3.0 in TextMate with the words “hello world” in it.
I did a spotlight search for Hello World but my file did not show in the list. I clicked Show All and it was not in the full list either.
With the full list open, I renamed my file from Foobar 3.0 to Foobar 3.0.txt and immediately, my file showed in the spotlight list.
So, Spotlight does filter files based on extension, and really does not like .0 extensions 🙂