Criminal Defense Attorney
Impossible to answer this question without a LOT more facts. But as a general rule, if you are getting a waiver or permission to "break a rule" or "modify an agreement," it's good practice to get that permission in writing.
If and until you and I sign an Agreement for Legal Services, I am not your attorney. These answers are provided for informational and/or novelty purposes.
Your question does not provide enough information for a full answer. Generally, any contract can be modified by a subsequent agreement--and in some cases by course of conduct. Any time the parties modify an existing contract, the modification should be in writing and signed by the party you want to enforce the modification against. It is very risky to rely upon verbal "permission" to do anything.