+\dt \cw{\-\-new\-passphrase} \e{file}
+
+\dd Specify a file name; the first line will be read from this file
+(removing any trailing newline) and used as the new passphrase. If the
+file is empty then the saved key will be unencrypted. \s{CAUTION:} If
+the passphrase is important, the file should be stored on a temporary
+filesystem or else securely erased after use.
+