FORTRAN 77 Language Reference

Restrictions for Fields

Fields that are type declarations use the identical syntax of normal FORTRAN type statements, and all f77 types are allowed, subject to the following rules and restrictions:

In a structure declaration, the offset of field n is the offset of the preceding field, plus the length of the preceding field, possibly corrected for any adjustments made to maintain alignment.

You can initialize a field that is a variable, array, substring, substructure, or union.