Character position definition and scope:

These ten character positions are undefined; each may contain a blank ( # )meaning Undefined or a fill character ( | ) meaning No attempt to code.

National Level Requirement for character positions 008/18-27 is Optional.

LC Guidelines:

 008/18-27  Undefined

For information on other 008 character positions, see:

008  Fixed-Length Data Elements

See also:

Variable Control Fields