I am wondering this too! What did you end up doing?
Hello,
In doubt I ended up sending a full copy of my passport.
They sent me my COPR back within a few days. They also sent back together with the COPR my cover letter and the copy of the bio page of my passport that I had sent them for PPR, so I would guess that they didn't need ALL pages of my passport, but in doubt I would send a full copy if I were you, just in case.