i read the HInit.c and found the following lines: case 'l': if (NextArg() != STRINGARG) HError(2119,"HInit: Segment label expected"); segLab = GetStrArg(); break; and i got from my log files following(part of HInit command) ......cmp/HInit -I /home/hts/HTS489/data/labels/mono.mlf -l -o /home/....... the -l switch have no values,so it has a default null value,right?