Deletes a list of values from a company attribute. Values are matched exactly, as stored strings — so a numeric or date attribute must be sent in the same form it was created in (1, not 1.0). Each value is detached from every opening, location, position, hiring goal, shift and available slot holding it before being deleted. Every value listed must be one the attribute holds or held: naming a value it never had deletes nothing and returns 422, while naming one already deleted succeeds, so the request is safe to retry.