The term "closed period" applies to a period before any regular reporting event (such as interim or final results) and is usually of two months' duration, during which time Directors and other "relevant" employees (those with access to price sensitive information) are not permitted to deal in the shares of their company. Many companies make it an in-house rule not to communicate with the Market during these periods, although this is not a regulatory requirement - this being said, they are still bound to report any events which are price sensitive regardless.