Creampuff,
The individual departments don’t write and hone the material. They come up with the bright ideas (policies) and tell OPC about them. OPC then drafts the Regulations to give effect to the bright ideas.
Creampuff, you are a bright individual, and obviously somebody with a passing interest in legal things, tell me, would organisations such as AMSA or NOPSEMA also operate in the same said manner as what you mention above in relation to CASA? Just curious really.