After some discussion with PG and with the TEI list, it seems that we should be doing this:

• Marking page breaks using a plain <pb> tag.
• Marking up the folio numbers (they're not page numbers if they cover a folio) using <fw type="folioNum">29</fw>.
• Since we'll now be marking up "forme works", we should probably also be marking up the running titles using teh same tag. That can be largely automated.
• Handling the printers' marks at the bottom left of folios in the same way.