5.2.1.2. Versioning. The API is implemented with its own separate versioning which, in its early stages, was represented by a single digit. Recently, at version 6 (also the current version), the semantic versioning approach was adopted. Additionally, the developers warn potential client developers that only even version numbers represent stable states of the web API. This versioning approach is similar to the one used in the Linux kernel where minor releases with an odd version number are not meant to be used in
production