The "MS:PUNCH" command allows you to insert slots in the corners of a parallelepiped.

Attention must be paid to the lines that need to be selected. In fact, it is possible to break into three of the four edges present in the parallelepiped. If you select to make the break on the visible edge all the lines must be selected, if you decide to make the break on one of the two partially visible edges, the selection of the second line at the bottom must be omitted.