Named after a U.S. Supreme Court case, Weingarten Rights give you the right to union representation whenever you are in a meeting or interview with management where disciplinary action may result.
In such cases, you should ask for a union representative to attend the meeting with you. A representative can be a shop steward or a staff representative from your Local office.
Do not go into the meeting alone unless you are absolutely sure that no discipline will result. Call your Staff Representative or Shop Steward as soon as possible.