There is no universal term. Different statutes label such provisions differently, but the label doesn't matter: what matters is what is prohibited.
For example, Ontario's Occupational Health and Safety Act s. 50 says:
No employer or person acting on behalf of an employer shall,
(a) dismiss or threaten to dismiss a worker;
(b) discipline or suspend or threaten to discipline or suspend a worker;
(c) impose any penalty upon a worker; or
(d) intimidate or coerce a worker,
because the worker has acted in compliance with this Act or the regulations or an order made thereunder, has sought the enforcement of this Act or the regulations or has given evidence in a proceeding in respect of the enforcement of this Act or the regulations or in an inquest under the Coroners Act.
This is found in a Part titled "REPRISALS BY EMPLOYER PROHIBITED" and the section heading is "No discipline, dismissal, etc., by employer."
Under British Columbia's Human Rights Code, s. 43 says:
A person must not evict, discharge, suspend, expel, intimidate, coerce, impose any pecuniary or other penalty on, deny a right or benefit to or otherwise discriminate against a person because that person complains or is named in a complaint, might complain or be named in a complaint, gives evidence, might give evidence or otherwise assists or might assist in a complaint or other proceeding under this Code.
That section is titled "Protection." And in public communications, the Human Rights Commission calls this "protection from retaliation."
So, just from two statutes and related communications, the terms used are:
- protection
- protection from retaliation
- reprisals prohibited
- no discipline, dismissals, etc.
You have presented two other alternatives in your question, and I am sure you can find many more.
But again, the labels do not matter. What matters is the substantive prohibition in the statute.
If you find it useful to use one of these general terms in communication, just choose one, explain what you mean by it, then use it in your communication.
