Just a couple of days ago I was editing a post which needed some formatting and re-tags. So I deleted the tag difference and inserted word-difference to be more clear and specific. Well, I tried to insert it! The tag word-difference got shrunk into difference. I repeated it again, thinking it might only be a glitch, but ended getting the same result. So I just submitted it with the formatting only.
Why does this happen? Are there any other tags too that get shrunk into more compact forms like this one or is it just a glitch?
Also if both are same in context meaning, why are two tags formed in the first place?