If you need to add a character to PERS1.xml you'll need to create an XML ID for them that uses four upper-case characters plus a number (e.g. GREG12). The ID you *want* to use may already be taken, but you can discover this by going to this page: http://figue.hcmc.uvic.ca:8080/exist/apps/myths/modules/detail.xqm?id=
and adding the ID to the end. The resulting page will either produce info on that ID or return a 404 not found. If you get the 404 you can use the ID.