Series of minor questions about OpenPGP 2

[Peter Thomas]

Hi again.

This is about signature types and how gnupg uses them.

I've looked through the signature types in chapter 5.2.1

1) The 0x02 standalone signature: What is its intended use (by the
standard) and is it ever used by gnupg?
I mean it's clear to me that it signs just it's own subpackets, but
how could this be ever used?

2) The 0x1F direct key signature: Is it ever used by gpg? I mean it
would perfectly fit for all subpacket types that apply directly to the
key, e.g. key expiration time (9), revocation key (12) or key flags
(27).
But gpg always puts these kind of information in the 0x13 signature.

3) Last but not least, the 0x50 3rd party signature. I must admit that
I absolutely don't understand its usage. Do you have an example? And
is this used by gpg?


Once again,.. thanks in advance.

Cheers,
Peter