Ceredigion council said Penrhyncoch was a Welsh-medium school and it was essential for Hafwen's teaching assistant to be able to communicate both through Welsh and British sign language.
Disliking constraints of any kind except those she imposed upon herself, she refused to sign a loyalty pledge when she was appointed to a teaching post at Idyllwild arts school and, in 1990, took the National Endowment for the Arts to court when it asked her to accept a no-obscenity clause in return for a grant.
Professor Martin Tippard, teaching dean at Dundee University Medical School, said students were now required to sign a code of practice pledging to act honestly.