Bearing is the term used to describe the navigation and directional trajectory of a course plotted for Starship movements.
Flight vectors are specified as an azimuth/elevation relative to the current orientation of the space vehicle. Bearing 000 Mark 0 is for instance a course direction straight ahead. As my rough diagram demonstrates, the first value represents an azimuth in degrees, the second describes the elevation. With this technique, all possible omni-directional spatial vectors can be plotted.
This system is further clarified by the term 'heading', which is a system involving navigational bearings calculated in relation to the galactic core, where Heading 000 Mark 0 is a course for the centre of the galaxy, which has no applicable relationship to ones current spatial location. It can be compared to directional measurements on a planet's surface, where bearings are based on degrees from north. Other celestial objects can be used for navigation beacons and rulers, particularly key stars, such as Canopus which is regularly nominated as a point of reference.