The Optimization (opt) interface () contains tools for setting up advanced optimization problems. The main purpose of the interface is its ability to set up objective functions, constraint contributions, and control variables that are defined locally only on certain geometric entities, as well as least-squares contribution with a time or parameter dependence.

The Label is the default physics interface name.

The Name is used primarily as a scope prefix for variables defined by the physics interface. Refer to such physics interface variables in expressions using the pattern <name>.<variable_name>. In order to distinguish between variables belonging to different physics interfaces, the name string must be unique. Only letters, numbers, and underscores (_) are permitted in the Name field. The first character must be a letter.

The default Name (for the first physics interface in the model) is opt.