ETRS89 Coordinates in a Degrees Minutes Seconds notation. Latitude hemisphere is omitted as irrelevant within GB.
Notation:
[Degrees Latitude], [Minutes Latitude], [Seconds Latitude], [Longitude Hemisphere], [Degrees Longitude], [Minutes Longitude], [Seconds Longitude] (, [optional ETRS89 ellipsoidal height])
Example:
50, 54, 26.42, W, 1, 49, 50.49, 0