You write:
In many environments (contract law eg.) there is a line above the
signature which defines the purpose for the signing and a line below the
signature which defines the role of the signer. Note that this is
dependent on the instance, and may vary ON A SINGLE CONTRACT if signed
more than once by the same person.
I don't see why these items cannot still be part of the (electronic)
document, with a reference to a person (e.g. the common name) appearing in
place of the usual signature. The roles etc. need not be in anyone's
certificate. When a person signs the whole document, he/she essentially
affixes his/her signature in all the places, and in all roles, where his/her
name appears. Won't that do it?
Charlie Gardiner