Is there any way to ask a template for a list of all the Attributes it uses?

It is possible to ask a given template for a list of attributes it uses. However, because an attribute may be used to specify the sub templates which are included and further expanded, it is not possible to get a definitive list of all attributes used/needed. It is possible to find out exactly what attributes a template has looked for during the template expansion. This is slightly different in that it is in the past tense.