-If nil, query user only when `plstore-encrypt-to' is not set.
-If neither t nor nil, doesn't ask user. In this case, symmetric
-encryption is used."
+If nil, query user only when a file's default recipients are not
+known (i.e. `plstore-encrypt-to' is not locally set in the buffer
+visiting a plstore file).
+If neither t nor nil, doesn't ask user."