Hand painted markings on transmission?

[Dodgerdart]

I've been looking at a lot of used 1999-2001 Camry's and some of them had black numbers hand painted on the top of the Automatic transmission. I looked at a 1999 that had "98" marked on the transmission. Just wondered what it means. Another Camry had other letter markings.

[humanoid]

I'm guessing the Camry at one point had it's tranny replaced with one from a '98 model year one.

[Tom 2000]

My transmission has that marking also, but it's "58".

[Dodgerdart]

Tom, has your transmission ever been replaced that you know of? I've seen 58 marked on one also. I thought they might be Salvage Yard markings as suggested but they seem to be on too many cars.
Anybody else got these markings on top of there transmissions? I'd hate to overlook a nice car and not buy it because I think it might have junkyard parts.