Semantic versioning (aka SemVer), is a widely adopted version scheme that uses a sequence of three digits (Major.Minor.Patch), an optional pre-release tag and optional build meta tag. In this scheme, risk and functionality are the measures of significance. Breaking changes are indicated by increasing the major number (high risk), new non-breaking features increment the minor number (medium risk) and all other non-breaking changes increment the patch number (lowest risk). The presence of a pre-release tag (-alpha, -beta) indicates substantial risk, as does a major number of zero (0.y.z), which is used to indicate a work-in-progress that may contain any level of potentially breaking changes (highest risk).