And now for some trivia:

For all the IMAC flying you will do, Paul's answer was correct.

But I learned something new from an IAC Aresti instructor at the Tucson Shootout - Julie Johnson. In PURE Aresti, the arrow does indicate direction of roll. I had never heard that before, but I have no reason to doubt Julie. She is Fred Johnson's wife and very active in the full size arena.

I don't think the full size pilots deal with roll elements any differently than we do - the arrow on the roll does not indicate the direction of the roll. But apparently this is different in what she called "pure Aresti."