It's not that. You can search for other words with only 3 letters like "dog, hey, pte, tep, etc". Any 3 letter word I've tested works, except for pet. Also, "collectible" has 11 letters. The word has been used many many times in countless threads, for example in the title of a thread that is currently on page 5 of this forum section.AshySamurai wrote: »collectible, collectibles - maybe noone used this words?
pet, pets - I tried "no pet" and all fine. So, seems you need 5 or more letters.