Modification rights?

I've received conflicting advice on whether to sell pose balls (especially couple poses and animations) with "mod" or "no mod" set. One person asserted that I had to allow modification to enable people to delink and adjust the balls, but that's not right, is it? Is there any other reason to permit modification? Right now I'm selling everything as no-mod no-copy, but I'm willing to permit mod if there's a good reason to do so.

You should be able to set the scripts and animations no-mod, if necessary, and leave the prims modifiable. That way they can edit the ball position without being able to do naughty things with the important parts.

You can mix permissions like that within the same object. The object will say (no modify) after its name but that will only mean something in the object is no-mod.

Ah, many thanks.