Yes, the order is important and your wish is granted - this is being listed when you type the command name without anything: > Usage: slicer <input> [input2] [main options] [output options - any number of these] > > Main options: [-L] [-l <lut>] [-s <scale>] [-i <intensitymin> <intensitymax>] [-e <thr>] [-t] [-n] [-u] > The 'Main options' line is pseudo-EBNF: options need to be listed in this order. And yes again - it's because no one is interested in writing command-line parsers... ;) hth Christian On 24 May 2011, at 01:21, bettyann wrote: > Yes, I too discovered that the order of switches matter. > > I understand that that makes the code easier to create. I just wish the 'help' message listed the required order of switches. It takes a long time to figure out if I'm doing something wrong or if I just need to move around the switches into some unknown order until they work. > > All in all, I use slicer often to create .png file to put in .html webpages. This works well when I want to share results with colleagues at a distance. > > Between slicer and the imageMagicK suite, I can usually get the .png that I want. But it all starts with slicer.