+.RB ` ! '
+then that character is removed. (Hence, if you really wanted to show
+the message
+.RB ` \- ',
+you need to pass
+.RB ` !\- '.)
+Conscientious script authors will prefix strings appropriately.
+.PP
+Pango markup may be used in message and headline strings if the
+.B \-m
+option is requested.
+.SS "Button specifications"
+A
+.I button
+argument has the form
+.RI [ opt \fB: opt \fB: ...] \c
+.RB [ ! ] \c
+.IR label .
+The
+.I label
+is either a text string, or a GTK stock-id (e.g.,
+.BR gtk-ok ).
+Mnemonic characters in button labels may be marked by prefixing them
+with underscores. Write two underscores if you really want a literal
+underscore to appear.
+.PP
+Each
+.I opt
+may be one of the following.
+.TP
+.B default
+This should be the default button, activated when the user presses the
+.I enter
+or
+.I return
+key.
+.TP
+.B cancel
+This should be the cancel button, activated when the user presses the
+.I escape
+key or simply dismisses the window.
+.TP
+.BI = tag
+If the user activates this button, output the
+.I tag
+rather than the button's label.