Federal regulations (rules passed by federal agencies) are published by the U.S. Government Publishing Office (GPO) first by date in the official Federal Register (Fed. Reg.) and then by topic in the official Code of Federal Regulations (C.F.R.)
The best source for the C.F.R. is HeinOnline, which provides complete scans of the C.F.R. from its first publication in 1938 to the present. Additionally, the library maintains a current print copy of the C.F.R. and the GPO provides authenticated, exact copies of the print C.F.R. in PDF format for every year from 1996 to the present:
The GPO stopped publishing the Federal Register in print in 2014 and now publishes it exclusively in an official, authenticated PDF version on its website. Both the GPO and HeinOnline provide complete PDFs of the Federal Register from its first publication in 1936 to the present.
The GPO also posts the Federal Register on its own separate website, FederalRegister.gov. In theory, the GPO considers this version unofficial but, in practice, FederalRegister.gov links to the official PDFs on the GPO's website and simply serves as a different search interface.
California regulations (rules passed by California agencies) are first published as proposed regulations by date in the California Regulatory Notice Register (Notice or Z Register), then as final regulations by date in the California Code of Regulations Supplement (Register), and finally by topic in the California Code of Regulations (Cal. Code Regs.) The Office of Administrative Law (OAL) publishes the Notice Register and, until 1990, published the Register and Cal. Code Regs. However, due to budget cuts, the OAL could no longer afford to publish the Register and Cal. Code Regs. and instead granted a license to publish the official versions to Barclay's, which has since consolidated with Westlaw.
Unfortunately, although Westlaw provides the complete text of the Cal. Code Regs. from 2002 to the present, only the print version is considered official and Westlaw does not authenticate the online version or provide PDF scans or other exact copies of the print version. For source collecting, you will need to access the Cal. Code Regs. in print or (for older editions) microfiche:
The California building code (Title 24 of the Cal. Code Regs.) is based on copyrighted model codes written by various building standards organizations. Because the codes are copyrighted, they are published separately from the other codes and updated every 3 years instead of continuously. Neither Lexis nor Westlaw have the right to publish the building codes but the library maintains a copy in print and the California Building Standards Commission links to exact copies of the print on the building organizations' websites:
The Notice Register and Register have turbulent publishing histories and obtaining copies of them often requires asking your editor to make an interlibrary loan request. However, the OAL's website provides free PDFs of the Notice Register from 2002 onwards that are exact copies of the print version. The library also maintains some older copies of the Notice Register in print and some older copies of the Register in microfiche: