where can I suggest changes to the SDF spec ?
A bit of context: I am one of the core developers of the robot construction kit (Rock, http://rock-robotics.org) and I've started to integrate SDF as the robot/world description format (since we had none, we decided to skip the URDF/SDF dichotomy).
Anyways, in the process, there are bits in SDF that I hope my suggestions could improve. I wondered where was the best place to suggest and discuss such proposals.