Nor anyone acting on its behalf

See also delegation.

That fabulous Latin construction nemo dat quod non habet ought, but does not, nix that tedious drafting construction: “neither X, nor anyone acting on its behalf, may do Y”.

For if, by the lights of the law, a principal has no right to do a thing, it follows as a matter of ineffable Latin logic that neither may her ox, ass, servant, agent, attorney, nominee, delegate or other mortal representative do that thing on her behalf: one cannot give what one does not have.

Now if such a representative independently happens to be entitled to do that thing, it is a different story, but still this ghastly confection won’t save you: such a representative would not thereby be acting under the contract at hand, nor really on the principal's behalf and thus wouldn't really be a representative, so this purported contractual stricture will fall upon stony ground.

So, be bold, young attorney: banish it from your lexical armoury.