Please avoid use of the term "key" without explicit qualifiers
The OpenPGP ecosystem has many different things that are called "keys". There are at least:
- transferable public key (a.k.a. "certificate")
- transferable secret key
- public key packet
- subkey packet
- cryptographic key material (without any packet framing)
I think this draft will be easier to read if everywhere it says "Key" with no qualifier, it uses either an explicitly qualified variant of "key", or an entirely different word.