Field help (ACTCODPAR) 

parameter codes for the action.

The order in which the parameter codes should be entered in the grid is very important : It must correspond with the order in which the parameters have been entered in the sub-program that allows the execution of the action.

Each parameter must have been declared in the parameters dictionary. Before creating this parameter code, verify that it doesn't exist already under another code in order to avoid redundancies. The selection key allows you to obtain the list.