The Capitol Guard was the official guard squadron for members of the High Council of Time Lords when they went on missions outside of Gallifrey. They were led by a commander. (AUDIO: Day of the Vashta Nerada)
The Guard had an Intelligence Division which reported to the President. It was dissolved by President Niroc and replaced with the Secret Security Committee. (PROSE: The Eight Doctors)
One guard detail went with Cardinal Ollistra as she travelled to Synthesis Station to assess Doctor Eva Morrison's work on artificially augmenting the Vashta Nerada for medical, military, and mining use. (AUDIO: Day of the Vashta Nerada)