TOTO: what is the standard tankl for a CST743E bowl?

[Isis]

My toilet rebate program is very specific in spelling out the tank and bowl product codes. Often in an ad the EcoDrake II, for example, will say that it's a CST744, which is the number of the bowl, but it won't specify the number for the tank, so I wonder if that is standard, or do I have to buy them separately?

[Terry]

The Drake and Eco Drake
Bowls:
C743E, round
C744E, elongated
C744EL, ADA
Tanks:
ST743E, Watersense 1.28 gallon
ST743S, 1.60 gallon

The Drake II with double cyclone
Bowl:
C454CEFG
Tank:
ST454E, Watersense 1.28 gallon