Please tell me what do you call "regulation", because I saw earlyer you use this term regarding transformers in place of "drop", which is a voltage or relative voltage change, but here the meaning is reciprocal, less regulation means more voltage change. You can overdefine terms for yourself, but would be better if you didn't use 1 term in 2 opposite meaning.
I advise you to not use term "regulation" for defining quantities at all, since it is always a source of ambiguity. Regulation is a process, involving at least 2 quantities, and if you want to describe its goodness with a single quantity, then it should be a ratio of the change in target quantity and the change in affecting quantity. As you can see in datasheets, for example "load regulation" is given in %/A or mV/A.