He told us that same story. It turns out that JPL does so much legwork for which they never get any credit. JPL wasn't allowed to logo anything or stamp any identifying marks from their shop. NASA is the big brother (translate - bully) and they don't like the spotlight to shine anywhere else. So when they were told that there needed to be this imprint put on the wheels to mark the sand, some joker came up with the idea to make that "identifiable mark" something that would poke big bully... er.... big BROTHER in the eye.

Now I know the story is true! (I mean, if JAY says it...!)

I am also surprised that it is still there. I was told this was done not for this mission, but for the FIRST rover!!!