Originally Posted by Tesla
Scott,

In Sacramento County, the AHJ DOES insist on red hats for MC.


http://www.southwire.com/commercial/nema-bulletin-90.htm

All of California is on basically the 2011 NEC, with CA Energy Code Amendments (2013 CEC)
They are only allowed to add their own local amendments to Building Codes under certain very limited conditions (seismic, climatic, etc)

I'd be willing to bet that the requirement isn't written down anywhere.

I personally use them even though they aren't required