choices:
- "choice"
+ "choice" [symbol]
<choice options>
<choice block>
"endchoice"
can be compiled as modules.
A choice accepts another option "optional", which allows to set the
choice to 'n' and no entry needs to be selected.
+If no [symbol] is associated with a choice, then you can not have multiple
+definitions of that choice. If a [symbol] is associated to the choice,
+then you may define the same choice (ie. with the same entries) in another
+place.
comment: