https://semver.org/, Semantic Versioning 2.0.0

Version number MAJOR.MINOR.PATCH == Incompatible_changes . New_functions . Bug_fixings with everything assumed to be backwardly compatible.

This is a very useful knowledge when choosing packages:

• Avoiding things like 0.x.y because API is not stable yet.
• Prefer >=2.x.y because at least it appears rolling forward.

Why Use Semantic Versioning? (Probably one should ask why not use it. Because anyway you need to have a rule for versioning. Unless you have a better choice and reason, just adopting the so far the best rule is a wise choice.)