CST743S, Regular bowl
CST744S, Elongated bowl
CST744SL, Elongated ADA height bowl
adding the "G" makes it Sanagloss, this only comes in the CST744SG
adding the "B" means the tank lid bolts down, handy in commercial bathrooms.
adding the "D" is for "insulated tank"
"DB" insulated tank with bolt-down lid.