Definition - What does Proscription mean?
Proscription is the dismissal of a legal action because it is already beyond the period in which it is allowable. In the case of insurance, it means a claim or any other demand made by a policyholder to an insurance company is already past the time before which it should have been made.
Insuranceopedia explains Proscription
In legal courts, a person is given a reasonable time to prepare and pursue an action. It considers the time for pertinent activities like the collection of the necessary documents that are going to be presented before the court. The proscription period sets a limit to these activities along with the appropriate legal action so that a case can then be tried and resolved within a reasonable time span.
The same is true with insurance claims and insurance demands from the insured. A company gives the insured a specific time frame in which they can gather receipts and any other important documents to settle a claim or at least get a response from the company. An act done after this period might waive the company's obligation to respond to it.