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Free-Form Subfield Definition

A free-form subfield definition begins with the subfield name, or it begins with the DCL-SUBF operation code followed by the subfield name.

The DCL-SUBF operation code must be specified if the subfield name is the same as an operation code allowed in free-format calculations. See Table 1.

The subfield name is followed by keywords, and finally a semicolon.

Program-described subfield

Specify *N for the subfield name if the subfield does not have a name.

If a data-type keyword is specified, it must be the first keyword.

If the subfield is a predefined subfield in the Program Status Data Structure or a File Information Data Structure, specify the subfield reserved word in place of the data type keyword.

In a free-form definition, the OVERLAY keyword can only be used to overlay one subfield on another subfield. If you don't want the subfield to be placed at the next available position in the data structure, use the POS keyword to specify the starting position.

Externally-described subfield

The first keyword for an externally-described subfield must be the EXTFLD keyword. If the subfield name is the same as the external name of the subfield, the parameter of the EXTFLD keyword may be omitted.

Subfield examples

See Free-Form Data Structure Definition for examples of free-form subfield definitions.

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