Yii Framework has recently declared that it has adopted the SemVer version for itself, applicable from its 3.0.0 version. The purpose of this adaptability is to create enhanced predictability and compatibility with the composer. In fact, the upcoming versions of extensions will also be adopting SemVer.
SemVer is said to be simple and is given a version number of MAJOR.MINOR.PATCH; each of these additions are explained as below:
MAJOR version for the times when you make incompatible changes in the API.
MINOR version for the times when you add any functionality in a backwards-compatible manner.
PATCH version for the times when you fix the bug in a backwards-compatible manner.
Learn more about the SemVer update, adopted by Yii.
News Source: Yii Framework