Several application variables determine what PGP keystores are in use and what options will be used for signing and encryption. A convenient dialog provides access to the values of these variables. There is no GUI for access to the contents of the keystores in use however. So it is necessary to specify the IDs of the keys to use for signing and en-/decryption.
As the dialog provides access to all the supported and required variables, it is normally not necessary to deal with them directly. However, they can be configured and used in exactly the same way as any other application variables. So it might be advisable to extract the definition of the required variables into a separate configuration variableset which can then be reused by several parties (other FileHandlers or even other applications). See the sample configuration for an example of such a setup.