Past Practices Limit Parties’ ChoicesHistory, frequency, maturity of relationship all figure in estoppelBy Gordon Sova08/23/2007|hrreporter.com|Last Updated: 10/04/2007 The term past practice refers to a long-standing and consistent procedure or interpretation on the part of either an employer or a union that has resulted in the other party relying on that procedure or understanding in their dealings. Legally, it creates an estoppel: when a party has declared through its actions (or inactions) that it intends to interpret its rights in a certain way, and others have relied on these representations, it cannot then revert to a stricter interpretation of what these rights are.What is the source of the right being contested?Past practice comes into play in three different situations when dealing with a collective agreement. In some cases, a practice has been common and accepted despite the fact that it is contrary to the contract. In other cases, a practice of long standing concerns a subject on which the agreement is silent. Finally, arbitrators will use past practice to discover the meaning that has been given to agreement language that is ambiguous. To Read the Full Story, Subscribe or Sign In Remember Me Forgot Password If you are a current Subscriber, please click here to set-up or update your login information.