in which case Pageant will prompt for the keys' passphrases (if any)
and start the agent with those keys already loaded. Passphrase prompts
-will use the controlling terminal if one is available, or the GUI if
-one of those is available. If neither is available, no passphrase
-prompting can be done.
+will use the controlling terminal if one is available, or failing that
+the GUI if one of those is available. If neither is available, no
+passphrase prompting can be done.
To use Pageant to talk to an existing agent, you can add new keys
using \cw{-a}, list the current set of keys' fingerprints and comments