Question about Nascar cards

[ZP9]

What do these letters mean when next to the listing:

Tony Stewart P/T/V/S

What do the P/T/V/S mean, and I have seen an O on some as well I think.

Thanks

 

[ZP9]

Ok, that makes total sense now. Thanks for answering the dumb question of the day Mark

 

[PhilM]

so..they insert the same card across several products?