You can specify a set of reserved keywords that the code generation process should not use, facilitating code integration where functions and variables from external environments are unknown in the Simulink® model. To create a list of reserved names, open the Configuration Parameters dialog box. On the Code Generation > Identifiers pane, enter the keywords in the Reserved names (Simulink Coder) field.
If your model contains MATLAB Function or Stateflow® blocks, the code generation process can use the reserved names specified for those blocks if you select Use the same reserved names as Simulation Target (Simulink Coder) on the Code Generation > Identifiers pane.