A nested structure declaration is one that is contained within either a structure declaration or a union declaration. You can use a previously defined record within a structure declaration.
Example: Define structure SALE using previously defined record PRODUCT:
STRUCTURE /SALE/ CHARACTER*32 BUYER INTEGER*2 QUANTITY RECORD /PRODUCT/ ITEM END STRUCTURE
In the above example, the structure SALE contains three fields, BUYER, QUANTITY, and ITEM, where ITEM is a record with the structure, /PRODUCT/.