My understanding that by "accepting" you mean "reading back" ?
I think when you use the word relay, you do not mean that the student
informs ATC that he is relaying ?

The CFI officially "accepts" the clearance, and (with a wink and a nod),
the student reads it back. I doubt ATC cares who is accepting the
clearance, so long as it is accepted (or rejected). No, the student (in
my sceneario) would not state that he is relaying a clearance, he would
just read it back.

He is, however, doing it under the authority of the CFII.

Jose
--
"There are 3 secrets to the perfect landing. Unfortunately, nobody knows
what they are." - (mike).
for Email, make the obvious change in the address.