The specific actions for TEI P4 documents are:
All actions described above are available in the contextual menu, the TEI
P4 submenu of the main menu and in the Author custom
actions toolbar.
A drag and drop with a file from the
Project view or from the DITA Maps
Manager view to a TEI P4 document that is edited in Author mode will
create a link to the dragged file (the ptr element with the
target attribute) at the drop location.