controls part of the filename for output. use __STD_OUT__ (exactly as written here) for the screen or standard logger. use filename to obtain projectname-filename. use ./filename to get filename. A middle name (if present), iteration numbers and extension are always added to the filename. if you want to avoid it use =filename, in this case the filename is always exactly as typed. Please note that this can lead to clashes of filenames. [Edit on GitHub]