These very fine distinctions between terms of art such as "void and unenforceable"on the one hand and"unlawful" on the other, are a little beyond my range of understanding.
They are terms of art.
If you do sometimes lose in clarity by adopting these terms of art, you do gain in certainty.
Those are going to be terms of art.
These are students whose intelligence is essentially non-verbal, but in terms of art they are highly talented.
One knows well that the phraseology of orders is arcane and that terms of art are used which are not normally applicable in other forms.
Phrases become "terms of art" only after they have become incorporated in some statute.
These words have a perfectly plain meaning and are not in any sense terms of art.