From a business perspective, an electrician should have a copy of NFPA 72, and be somewhat familiar with it in order to get extras! For some reason there might be 900 smoke detector on the project, and if I missed one on the Contract Drawing, that is picked up by the EC, the one extra detector always costs $2,000! I'm being funny [Linked Image], but there is lots on $$$ in change orders if you can pickup on missing stuff.
Of course I'm glad that not to many folks know 72, so that when I screw up on a design, it doesn't get thrown in my face.
That concept applies to many areas of NFPA 70 too!

Ron