The strange Hibernate version numbers

I am fascinated with Hibernate version numbers. Have you noticed how uncommon they are ? In the open source community, almost every project follows the same rules :

For example :

or

If necessary, you may append release specific modifiers :

Hibernate does not follow those conventions. You may find :

If you are used to Maven, then you must have been annoyed with it, as the resulting artifacts never follow the same conventions (with or without dash, uppercase or not, …).

Pretty frustrating. As a widely used library, I would expect Hibernate to follow the most common versioning schemes…