DOCBOOK: Marking up C preprocessor symbols

[Sean Kelly <kelly@ad1440.net>]

Folks:

Short of a customization layer to Docbook 3.0, how are you marking up C
preprocessor symbols?  For example, I want to add value by marking up
the symbol mentioned in the this paragraph:

<para>To prevent the conflict, define the C preprocessor symbol
NO_AUTO_NAMESPACE before including this file.</para>

(A colleague suggested <literal>.  I suppose, but it's just so ...
literal!)

Thanks.
--Sean