Type Declarations within Record Structures

The syntax of a type declaration within a record structure is identical to that of a normal Fortran type statement.

The following rules and behavior apply to type declarations in record structures:

%FILL can be specified in place of a field name to leave space in a record for purposes such as alignment. This creates an unnamed field.

%FILL can have an array specification; for example:
```
  INTEGER %FILL (2,2)
```
Unnamed fields cannot be initialized. For example, the following statement is invalid and generates an error message:
```
  INTEGER %FILL /1980/
```
Initial values can be supplied in field declaration statements. Unnamed fields cannot be initialized; they are always undefined.
Field names must always be given explicit data types. The IMPLICIT statement does not affect field declarations.
Any required array dimensions must be specified in the field declaration statements. DIMENSION statements cannot be used to define field names.
Adjustable or assumed sized arrays and assumed-length CHARACTER declarations are not allowed in field declarations.