the format for the version number is:

    aa.bb.cc[.dddd]

where:

aa = Version Number - a change to this means that the base software has changed in a fundamental and important way.

bb = Major Release Number - a change to this means that there have been significant changes to the look & feel and operation of the software.

cc = Minor Release Number - a change to this means that small features have been added and problems addressed.

[dddd] = Hot Fix Release Number (optional - may not appear) - a change here means that a problem has been addressed that needed quick resolution for one or more specific customers.