An external text file or files in which you define custom objects using a specific syntax. Custom object files normally have a .cst extension in their filenames. OpenEdge includes two custom object files for you to use: progress.cst and smart.cst. Both files reside in DLC/src/template.
Custom object files let you control how three AppBuilder interface components ¾ the Object Palette, New dialog box, and Choose dialog box ¾ present objects to the user for selection. By editing a custom object file or by creating your own, you can prepare the presentation of your own set of objects.