I know it's been mentioned that you can try tricks such as .jpg or using quotations as in "two" but these are unreliable. I tried searching for the word gag in the classic TZ forum using quotations and got the error message. I tried it with a period before gag and got only one hit and that was the first 3 letters for Gage Clark in only one thread. Putting a period after the word will work in probably all situations or at least all the 3 letter words I've tried.