Take a look at the back of my R315 Travis Jackson card. (And No! I did not write on the back of the card...

) But it is interesting... It says "R315" and "with position + team name in the bottom boarder"... And "border" is mispelled as "boarder"...
Perhaps someone in the 80's wrote this after looking at a baseball card catalog... But (and perhaps I am stretching it a bit) perhaps one of the hobby pioneers owned this card at one point and wrote this on the back... Burdick? Lionel Carter? Do any of you have any writing samples of Burdick or Carter (or anyone else) that look similar to this? It would be really cool if I could trace the ownership of this card back to one of the hobby pioneers...