Whenever possible, each leg will start and finish at a clearly defined topographical feature such as a lake, knoll, saddle, stream junction and so on.
The object is to split the overall route into sections that can be readily undertaken in conditions of poor visibility such as in cloud, fog or at night.
In addition to the compass bearing, for each leg the total distance will be measured as well as the height gained or lost and the steepness of the ground.
A copy of the route card is then left with a responsible person so as to assist the emergency services in the event that the group should suffer a mishap.
Nowadays, it is typical to enter the co-ordinates from the route card into a handheld GPS unit and use this in conjunction with a compass if conditions deteriorate.