![]() | The examples and perspective in this article deal primarily with the United States and do not represent a worldwide view of the subject.(July 2021) |
A grandfather clause (or grandfather policy or grandfathering) is a provision in which an old rule continues to apply to some existing situations while a new rule will apply to all future cases. Those exempt from the new rule are said to have grandfather rights or acquired rights, or to have been grandfathered in. Frequently, the exemption is limited; it may extend for a set time, or it may be lost under certain circumstances. For example, a grandfathered power plant might be exempt from new, more restrictive pollution laws, but the exception may be revoked and the new rules would apply if the plant were expanded. Often, such a provision is used as a compromise or out of practicality, to allow new rules to be enacted without upsetting a well-established logistical or political situation. This extends the idea of a rule not being retroactively applied.
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The Extended Security Update (ESU) program is a last resort option for customers who need to run certain legacy Microsoft products past the end of support.
The NHL has 60 referees and linesmen under contract and among them are 11 men who do not wear helmets. This is allowed through a grandfather clause in the collective agreement between the NHL Officials' Association and the league, which made wearing helmets mandatory beginning with the 1988–89 season. However, just as the NHL did with its players when helmets became compulsory for them in 1979, a grandfather clause was inserted in the agreement. All referees and linesmen who were employed on or before Sept. 1, 1988 did not have to wear a helmet.