Longer answer: the only guarantee that's carved in stone is that in X.Y.Z is backwards-compatible for all values of Z. Past that YMMV, e.g., typically X.Y+1 will be network-compatible for rolling upgrades, but we'll maintain disk-compatibility for longer.
Longer answer: the only guarantee that's carved in stone is that in X.Y.Z is backwards-compatible for all values of Z. Past that YMMV, e.g., typically X.Y+1 will be network-compatible for rolling upgrades, but we'll maintain disk-compatibility for longer.