%TEI.extensions.dtd

This entity is embedded in the TEI DTDs after the TEI element classes are embedded, and immediately before the base tag set and additional tag sets selected by the user are embedded. By default, the entity expands to the empty string; the user can override this default by declaring the entity with an appropriate value, typically this will take the form

<!ENTITY % TEI.extensions.dtd SYSTEM 'project.dtd' >