Experienced DOS or UNIX based GAMS users are used to having command line parameters associated with their GAMS execution commands. In the IDE a box is available just to the right of the execute button where we can associate a set of execution time parameters with a file. In turn note the IDE will remember these whenever the file is opened in this project in the future.
The IDE saves this file specific parameter information in the project file. This is particularly useful for save and restart parameters as once they are defined they are associated with every subsequent use of the file provided you're using the right project and have not changed the restart information.