Identifying your private key by the public KeyID

[Kenneth Jones]

Good day, and hello to the autoresponder (%]##{}#%^!!!) (just my opinion, mind you).
I've been toying with PGP GPG GnuPG and whatever on and off since mid 1995, but recently have become interested again as the political situation in the US seems to warrant it. (Warrant? We don't need no stinking warrants...) anyway...

I have a question about procedure...nomenclature, actually.  Is it normal to refer to the private key by its own keyID, or by the KeyID of the mating public key? The public fingerprint is the one known by others (natch) and it's the identification I associate with the key pair. Is there any time when it is appropriate to refer to my private key by its own KeyID? I understand that each of the two eight-character sequences is unique, and so the private key is in fact not accurately identified by using the public key's ID, but is it common to do so? Seems to me it would be less confusing (for me, any way) to be prompted with the Main KeyID than with that of the private key.