Mark-V speedtronic cards

I need to know the importance of revision level when purchasing Speedtronic cards, especially Mark V.
Suppose I request for DS200TCPDG1A and someone quotes me DS200TCPDG1 and does not mention revision level... does it work properly with the existing system?

Is it important to get the same revision level while purchasing a Speedtronic card?

Please advise...

mascontrdco @ yahoo. com