Evergreen
An evergreen is a press release or article that is not time-bound and therefore could be distributed or published at any time. In this way, publicity can still be generated during a period when there is little news to report. The evergreen can also generate attention over a longer period of time.
Evergreens, for example, can be written about a commercial or social development that occurs over a long period of time within an organization, or about a particular unique selling point. To be seen as relevant and newsworthy, it is important that the message contain an original angle.