Ancillary was, in the words of Rex Matheson, "a paper chase. A guaranteed way to lose something in the system". The ATF asked the CIA about information on a warehouse in Washington DC, but Brian Friedkin forwarded the request on to the ancillary three times. (TV: Dead of Night)
The Doctor's TARDIS had an ancillary power station. (AUDIO: The Haunting of Thomas Brewster)