There is a section of TEI under the "Guidelines" menu item called Customization. Issue 1813 https://github.com/TEIC/TEI/issues/1813 points out some problems that are eminently fixable. However, what Syd and I were unable to determine is where the source lives (other than on disk) and how to edit the file(s). Help appreciated. Signing off as the September Issue Assigner. best, --elli