While in the PL/I perspective, PL/I source files (.pli) referenced from other PL/I source files using an %include statement (for example, %include 'programname.pli') are recognized by the IDE as include files and appear in the PL/I Explorer in the PL/I Include Files virtual folder. The IDE does not compile the files in the PL/I Include Files folder and does not support setting Compiler directives on them.
If such .pli files no longer need to be (or should not have been) used as include files and you remove the %include statements, the IDE does not move the files automatically to the PL/I Source Files category and they are still treated as include files. You need to indicate manually that a .pli file shown in the PL/I Include Files folder is a PL/I source file:
This updates the information in the project about this file and moves the file to the PL/I Source Files folder of the project.
Alternatively, you can do one of the following: