"Our altitude climb instruction was "climb level Two Hundred". We read back the clearance and began the departure. As we began to climb we had some confusion as to what the altitude clearance limit was as we were unsure what level Two Hundred meant. We levelled at Two Thousand feet to ensure we didn't exceed any altitude limits.
The correct time to solve that conundrum was before the wheels left the ground; i.e. during the read back.