Nix is a word from colloquial German and means nothing, which is nearly what this command does. The command is intended to help multitask Qmon, a monitor program published by Qjump. When the command is issued, a dummy job named Qmons Nix-Job is created. If the monitor is started to examine this job, for example by entering:
(assuming that the dummy job has the job number 4), Qmon can easily be switched on and off.