First int (1) : The overall release version, this is usually a final release for the plugin/mod
Second int (2) : This signifies medium changes in the stated release (1), examples include major bug fixes, small new features that will work with a lower version, without too much modification
Third int (3) Small updates, eg minor bug fixes, and very minor new features.
We would rather you have a version such as:
As this shows that only minor modifications have been made, as oppose to 2.4.9 -> 2.5.0 (unless this is true and a major modification has replaced minor modifications)