Repository home page does not show v3

Landing on the repository one can see all spec versions up to 2.2
There is a branch with a v3 that is not visible unless one knows where to look.
Wondering what's the situation, one can imagine that maybe:
- v3 was never completed and did not get merged
- v3 is not merged into master due to a simple oversight
- the is just a different convention in managing the branches