These positions specify the line on the page in which the field begins.
The entry must be right-aligned; leading zeros are optional. Line numbers can be specified for either named or unnamed fields within a record. If you specify a line number for one field within a record, you must specify either a line number in positions 39 through 41 or a plus value (+n) in positions 42 through 44 for all fields within that record.
Line numbers are not valid if one of the skip or space keywords has been specified at either the record level or field level. Line numbers are valid, however, if one of the skip keywords has been specified at the file level. (Space keywords are not valid at the file level.)