To add a Deck opening click on the Add… in the Deck Info dialog box.  The following dialog box will appear:

In this dialog you specify the shape and location of openings in the current deck(s).  If the dialog box is opened using the Add button the appropriate fields will be set.  The values of these fields will be the same as those of the opening highlighted in the Openings field of the Deck Info dialog box when the Add… button was clicked.

Opening Location defines where the opening will be situated in the deck.  The opening insertion point is defined by an Offset and Longitudinal Position and also where the opening insertion point is in relation to the opening.

The Shape radio buttons define the shape of the opening to be added.  Five shapes are available and any number of shapes may be added to a deck.

The dimensions fields are relative to the opening and the fields required (for the particular shape chosen) are editable, while those not required are greyed.