The code for CA is the 1997 UBC, but california has made some changes, repackaged and resold the code as the 2001 CBC. Some municipalities in California don't care if you list the 1997 UBC as the code you designed by. I have received plan checks where the only comment was that I designed to the wrong code. The only change I had to make was that the package is now done per 2001 CBC, not the 1997 UBC. It's like Wisconin, New York, and North Carolina (off the top of my head). They've all adopted the IBC for the entire state, but they've repackaged it with a different title page and made it the "Your States Name Here" Building code. I own several copies of essentially the same code with different title pages. Most the changes I've found are administrative or very sublte in the text. The whole thing could probably have been handled with a fifteen page addendum (ie Georgia has a free pdf download) instead of another $80 book. But then the states wouldn't be able to generate any revenue.
I realize that this is the wrong place to rant, this was going to be a two line response, but...well it just got me going.