The Register contain notices of proposed regulatory actions and final regulations filed with the Secretary of State.
The California Code of Regulations consists of 28 titles that contain the codification of state agency regulations.
Barclay's Official California Code of Regulations (prior to 1990 called the California Code of Regulations):
State registers and regulation tracking are offered by Lexis, found on its Administrative Codes & Regulations.
In Bloomberg Law, proposed, final, emergency, temporary, and interim rules, plus regulatory notices can be found under Rulemaking within the State Laws & Regulation collection.