In a Progress Developer Studio for OpenEdge project, you can exclude or include compilable resources (like .p, .cls, or .htm) from your project build. Exclude from Build excludes the selected resources from the build and Include in Build includes the resources that were excluded from the build previously. You can access these options from the context menu of the resource or from the Source tab of the Build properties page.
Note: See Editor Colors options and Editor Build options for the list of compilable file extensions defined for your project.

The excluded resources entries are saved to the Excluded node on the Source tab, and only the entries that are present under the Source tab are considered for building. The Progress Developer Studio for OpenEdge compiler checks the exclusion entries before compiling a file. Once a file is excluded, then the r-code of that file is deleted. If the earlier excluded file is now included, then the respective file is compiled and the corresponding r-code for it is created. The project is compiled (r-code is generated) only when the relative path of the project being included does not match with any other resource relative path, which is at the top of order on Source tab.

When you remove the ROOT node or last existing node from the Source tab, a warning message appears as Removing all entries from the Source tab results in no resources being built: 'Do you want to continue?'. Only the entries that appear under ROOT node on the Source tab gets built automatically. However, you can manually compile the files in your project.