It would be nice to have a substitution parameter to fetch the name of a base template. There is a substitution parameter to retrieve the name of a template: %Template%, but none to retrieve a parent/base template.
Perhaps to cover multiple levels of template inheritance, a schema similar to that used by elements and event frames could be used.
%Template% = template of the current object
%..\Template% = base template of the template of the current object
%..\..\Template% = base template of the base template template of the template of the current object
...
