The EXFMT operation is a combination of a WRITE followed by a READ to the same record format (it corresponds to a data management WRITE-READ operation). If you define a WORKSTN file on the file description specifications as a full-procedural (F in position 18) combined file (C in position 17) that uses externally-described data (E in position 22) the EXFMT (execute format) operation code can be used to write and read from the display.