After the global structure parameters required for snow/wind loads (envelope, spacing, and depth) are defined for the Algerian snow/wind code DTR C2-47/NV99, you must also specify the parameters for snow/wind and sand loads.
The Snow/Wind Loads dialog has the following 4 tabs:
In addition to the standard buttons OK, Cancel, Help, at the bottom of the dialog there are the following 2 buttons: