In an old thread, our webmaster wrote:
Another oddity of the search function is that it ignores all "words" of less than three characters. So, it will ignore 68 and work on 1968.
We have some TDPers with usernames of two letters and you can't search usernames for these folks either.
I have also noticed that in addition to this, when you go to a User Profile of someone with a two-letter username, you cannot use the link that shows all previous posts of that person, that function will not work either.