On the PVP homepage, there are mentions of “patch-level” changes, in an example. In the A.B.C.D versioning system, would the D then be the patch level? Why does PVP mention patches at all, wouldn’t it be enough to distinguish major from everything else? I don’t understand why we couldn’t do with a more limited vocabulary in PVP.
It seems to me, that if the major version matches, then compatibility is assured. If we start distinguishing some minor changes from others, what have we gained? I suppose in practice, one could imagine minor/patch level changes that are more or less invasive. For example, people that are opposed to Hackage revisions could republish the package with updated bounds with only a patch level bump, and they’d argue that this is less risky than a source change which might affect optimization. But this is surely out of scope for the PVP, right?