California Code, Government Code - GOV § 27322.3

If the recorded instruments, papers, or notices or the record books in the office of the recorder have been microfilmed for preservation purposes, a type of record book may be used that will permit the removal of leaves in order that reproduction may be made in an efficient manner.

In order to microfilm or otherwise reproduce the record books for preservation purposes, permanently bound record books may be disassembled and after they have been copied the books shall be rebound in a type of record book that will permit the removal of leaves in order that reproduction may be made in an efficient manner.