OpusVersions

Possible version schemes:

Scheme 1: A.B.C.D

• A=1
• B is the RFC version
• C is for feature improvements
• D is for bugfixes

Scheme 2: A.B.C

• A is the RFC version
• B is for feature improvements
• C is for bugfixes

Scheme 3: A.B.C

• A=1
• B is the RFC version and for feature improvements
• D is for bugfixes

Scheme 4: A.B.C

• A is the RFC versions that aren't both backward- and forward-comparible (e.g. extensions)
• B is for feature improvements and RFC versions that are both backward- and forward-comparible (e.g. clarifications, minor fixes)
• C is for bugfixes

Scheme 5: A.B.C

• A is for any new RFC
• B is for feature improvments compliant with A
• C is for bug fixes

Scheme 6: A.B

• A is for features and RFC changes
• B is for bugfixes

This is Scheme 3 with the initial '1' dropped.