There is a strict set of rules (a protocol) on how the forecast is written, and it has a limit of 370 words. It is always said in the same way and is around 9 minutes long. The language of the forecast is hard to understand unless the listener understands how the rules work. For example: People listening to the forecast who know the protocol can understand it as "In the English Channel, there are strong winds, followed by a stronger wind in less than twelve hours time with some light rain, but good visibility". The numbers refer to the Beaufort Scale of wind strength. "Imminent" means within 6 hours, "soon" between 6 and 12, and "later" meaning after 12 hours. There are lots of other jargon used in the Shipping Forecast.