How to handle replaceable element inside code listing?

[fbolton]

This is tricky. In DocBook, replaceable text inside a code listing is generally styled as italic. In AsciiDoc you could potentially allow this styling by prefixing the code listing with [subs="quotes"]. Unfortunately, however, this is rather dangerous, because it enables all kinds of text styling, which typically makes a mess of any code listing.

This also affects the replaceable element more generally. Whatever we decide to do with replaceable inside a code listing must be consistent with the conversion outside of a code listing. Maybe resort to enclosing inside angle brackets?