Slitherine

I had followed a couple threads about when/how Regimental Guns can shoot. It seemed like there was going to be a FAQ about them to clarify. Is this somewhere? I didn't see anything in the 1.07 errata.

We had a couple instances this weekend where right-hand musket bases were shooting + regimental gun and left-hand bases without. Was there ever any clarification beyond the "consider the regimental gun in the central file?"