Use DISPLAY_REG_DELETE_VALUE when you want the action to be performed on the display host's registry (the local host when the application is run with a standard runtime; the thin client when the application is run with the thin client). Use REG_DELETE_VALUE when you want the action to be performed on the server host's registry (the local host when the application is run with a standard runtime, and the application host when the application is run with the thin client).
CALL "REG_DELETE_VALUE"
    USING OPEN-KEY-HANDLE, VALUE-NAME,
    GIVING STATUS-CODE 
               | OPEN-KEY-HANDLE Usage unsigned-long | Handle of a currently open key or one of the following predefined handles of keys that are always open (defined in 
                              acugui.def): 
 | 
| VALUE-NAME PIC X(n) | Name of the value to delete. If NULL or an empty string, the value set by REG_SET_VALUE will be deleted. | 
| STATUS-CODE Numeric data item. | Receives the return status of call to Microsoft's RegDeleteValue function. A return status of zero indicates success; non-zero indicates that an error occurred. | 
The key identified by OPEN-KEY-HANDLE must have been opened with KEY_SET_VALUE access (KEY_WRITE access includes KEY_SET_VALUE access).