A neither field is used neither for input nor for output. A neither field is valid only for join logical files. It can be used as a join field in a join logical file, but your program cannot read or update a neither field.
Use neither fields when the attributes of join fields in the physical files do not match. In this case, one or both join fields must be defined again. However, you cannot include these redefined fields in the record format (the application program does not see the redefined fields.) Therefore, redefined join fields can be coded N so that they do not appear in the record format.
A field with N in position 38 does not appear in the buffer used by your program. However, the field description is displayed with the Display File Field Description (DSPFFD) command.
Neither fields cannot be used as select/omit or key fields.