This option defines a new support. Open the dialog, by clicking 
on the Supports dialog. It has the following tabs:
- Rigid Support
- Elastic Support
- Support with gap
- Support with Friction
- Support with Damping
- Nonlinear Support.
The options available on the individual tabs differ based on the type of support and structure selected.
Clicking Advanced, which is available for nodal and linear supports (not available for planar supports), opens a new dialog: Support definition - Advanced.