MAP field-declaration [field-declaration ] END MAP
Each field declaration can be one of the following:
Type declaration, which can include initial values
Substructure--either another structure declaration, or a record that has been previously defined
Union declaration--see "UNION and MAP" for more information.
STRUCTURE /STUDENT/ CHARACTER*32 NAME INTEGER*2 CLASS UNION MAP CHARACTER*16 MAJOR END MAP MAP INTEGER*2 CREDITS CHARACTER*8 GRAD_DATE END MAP END UNION END STRUCTURE