These descriptors cause subsequent values to be transferred starting at a different column position in the record. They can, for instance, be used to set up a table with headings positioned over each column. In all these descriptors the value of n must be 1 or more. Columns are numbered from 1 on the left (but remember that column 1 may be used for carriage-control if the output is sent to a printer).
On input TLn can be used to re-read the same field again, possibly using a different data descriptor. On output these descriptors do not necessarily have any direct effect on the record: they do not cause any existing characters to be replaced by blanks, but when the record is complete any column positions embedded in the record which are still unset will be replaced by blanks. Thus:
WRITE(UNIT=LP, FMT=9000)
9000 FORMAT('A', TR1000, TL950, 'Z')
will cause a record of 52 characters to be output, middle 50 of
them blanks.