[mgkimsal]

or maybe just 'version numbers'.

HR3361.4 HR3361.5 HR3361.6

etc

Easier for everyone to understand, not just geeks...

[dllthomas]

People get tempted to play shenanigans like reusing numbers.

[mgkimsal]

datetime?

HR3361.20141106142502

almost as bad as hash, but immediately parseable and understood if a version was before or after something else.