-By default, PGG uses GnuPG, but Pretty Good Privacy version 2 or version
-5 are also supported. If you are new to such a system, I recommend that
-you should look over the GNU Privacy Handbook (GPH) which is available
-at @uref{http://www.gnupg.org/gph/}.
+By default, PGG uses GnuPG. If you are new to such a system, I
+recommend that you should look over the GNU Privacy Handbook (GPH)
+which is available at @uref{http://www.gnupg.org/documentation/}.
+
+When using GnuPG, we recommend the use of the @code{gpg-agent}
+program, which is distributed with versions 2.0 and later of GnuPG.
+This is a daemon to manage private keys independently from any
+protocol, and provides the most secure way to input and cache your
+passphrases (@pxref{Caching passphrase}). By default, PGG will
+attempt to use @code{gpg-agent} if it is running. @xref{Invoking
+GPG-AGENT,,,gnupg,Using the GNU Privacy Guard}.
+
+PGG also supports Pretty Good Privacy version 2 or version 5.