In this step, you define the editing mask for the assignment of keys when creating capital investment program positions. The system determines the editing mask that is to be used using the key of the editing mask and the initial positions of the program position key entered. When these agree, the system tries to adapt the key entered to the mask. If this attempt is unsuccessful, the system outputs an error message. In this way, you can guarantee that the keys of the positions in a program will all have a given structure.