An agent of depository shall retain each document relating to an addition of a security, a withdrawal of a security, or a substitution of securities, or a copy thereof, for a period of not less than two years after such addition, withdrawal, or substitution is effected; provided, however, that nothing in this Section shall be deemed to require an agent of depository to retain a security or a copy thereof.
Cal. Code Regs. Tit. 2, § 16001.5.4