Well sure, valid is overloaded just as accepted is which we nevertheless
use
for the "accepted" taxonomic relation. Leaving aside what the actual term name is, validNameUsage, correctNameUsage, amendedNameUsage or sth else - it seems to fix the problem, doesn't it?
Perhaps, but I guess because of the ambiguity issue with "valid", I'm not completely sure which specific problem is being solved in this case. If, as from Tony's original email, it is to link a nomen nudum usage instance to its corresponding validly published/available usage instance, that makes some sense. But then do we need something similar for Emendations (e.g., emendedUsageInstance) and other sorts of nomenclatural relationships? How many of these "foreign keys" will we ultimately need? This is why I'm thinking in terms of something more relational.
My hope would be that we only need one for a nomenclatural relationship and use the nom status to specify its exact meaning. But of course you could have multiple relations and then this method won't work. At least it would allow us to publish most of the data in a simple way before one has to step into the relationship extension.
Markus