(a) to become or remain a member of a union or a particular union; or
(b) to cease to be a member of a union or a particular union; or
(c) not to become a member of a union or a particular union; or
(d) in the case of an individual who is authorised to act on
behalf of employees, not to act on their behalf or to cease to act on their behalf; or
(e) to resign from or leave any employment on account of the
fact that the other person is or, as the case may be, is not a member of a union or of a particular union.