"system code" and "record type"?

\"system code\" and \"record type\"?

When I define the edit rule of DD item,I chose "UDC" for Rule. Then the "system code" and "record type" display.
what do these parameters mean?
in the help document,"System Code A user defined code (98/SY) that identifies a J.D. Edwards
system.
Record Type A code that identifies the table that contains user defined
codes. The table is also referred to as a code type."
But I still can not understand . who can help me.

Re: \"system code\" and \"record type\"?

The system code (DD alias SY)refers to a module ID. eg. 01 is Address Book, 04 is Accounts Payable, 09 is General Accounting ... The record type or User Defined Codes (table) (DD alias RT) refers to a collection of codes/values that are alternative values that can be entered into a field. For example, start Address Book revisions (menu G01) (Application P01012). Click in the field "search Type" and click on the little torch on the right of the field. This will give you a list of valid codes/values that can be entered into the field "Search Type". This list is contained in the UDC table where the system code is 01 and the record type is ST.

Re:

Thank you very much.