Versions in Maxim Money have 4 numbers, i.e. A.B.C.D (1.7.4.2 at the time of writing). Each number increments as follows:
A: When we start a new version from scratch (this number will likely never change!)
B: When the software gets a major new enhancement
C: When the software gets a moderate enhancement
D: When the software gets a very minor enhancement and/or bug fixes only