What it means when I sign keys

   *** GPG ***
   (0) I will not answer. (default)
   (1) I have not checked at all.
   (2) I have done casual checking.
   (3) I have done very careful checking.

   *** Mine ***
   (2) I was presented with a couple valid looking ids. say at a keysigning person.
   (3) I know this person, that is their name, that is their email address.