The man responsible for explaining OS and Network topics for masses. The professor who "attacked" programmer. From Computer Networks Book DNS section "Take th

The man responsible for explaining OS and Network topics for masses. The professor who "attacked" programmer. From Computer Networks Book DNS section "Take the pro domain,for example. It is for qualified professionals. But who is a professional? Doctors and lawyers clearly are professionals. But what about freelance photographers,piano teachers, magicians, plumbers, barbers, exterminators, tattoo artists, mercenaries, and prostitutes? Are these occupations eligible? According to whom?"