This is a new (v4.x) function accessible via the Sidebar (options 3-2) and lists all standard missions available at the momenttime. When the Skunk enters a new zone or sector all the all available mission will be added to the BBS. The exception Exceptions are the hidden or secret missions. In : in order to add them to the BBS they must first be found by flying close to the surface of stations . Mission (same as prior to v4.x). Missions will stay in the BBS for a limited amount of time or until you go out of range such as when travelling through a Jump Gate.
Please note that if you're loading an existing save after updating to version Rebirth 4.0, you'll need to change zones before the BBS will begin to populate.