File: Examples\Constants\DKLang_Constants_Demo.dpr
This is a little bit more advanced example on DKLang Package usage.
When you click the Test button, a message box is displayed, with the text taken from a constant. You can edit the project constants ONLY by using Project | Edit project constants... menu item. Don't edit the .dklang file directly as its contents is generated and updated automatically!
Notice constant resource link directive in the project source file (.dpr):