I've got some text, for example:

    <par>
This booklet comes from the Majjhima Nikāya MN-36, the Mahāsaccaka Sutta, The Greater Discourse to Saccaka, given by the Buddha and is taken from the translation by Bhikkhu Ñāṇamoli and Bhikkhu Bodhi.
    </par>

and I would like to set the "MN-36" in small caps. I assume I'd have to markup the "MN"? Or is there some automajic way that I can express in CSS that every "MN-" should be set in small caps?

You would have to add markup. You could use JavaScript to add the markup, if you like.

Wait... Prince has a Javascript interpreter?

Because the XML (or better, XHTML) file is generated by Python, I could just extend the Python script to sprinkle markup into the generated file.

Yes, Prince can run basic JavaScript. We're still working on adding more DOM support.

If you're generating the document from Python then that would be the best place to do it.

Very schnufte, thanks Mike