California Code, Corporations Code - CORP § 408

(a) A corporation may adopt and carry out a stock purchase plan or agreement or stock option plan or agreement providing for the issue and sale for such consideration as may be fixed of its unissued shares, or of issued shares acquired or to be acquired, to one or more of the employees or directors of the corporation or of a subsidiary or parent thereof or to a trustee on their behalf and for the payment for such shares in installments or at one time, and may provide for aiding any such persons in paying for such shares by compensation for services rendered, promissory notes or otherwise.

(b) A stock purchase plan or agreement or stock option plan or agreement may include, among other features, the fixing of eligibility for participation therein, the class and price of shares to be issued or sold under the plan or agreement, the number of shares which may be subscribed for, the method of payment therefor, the reservation of title until full payment therefor, the effect of the termination of employment, an option or obligation on the part of the corporation to repurchase the shares upon termination of employment, subject to the provisions of Chapter 5, restrictions upon transfer of the shares and the time limits of and termination of the plan.

(c) Sections 406 and 407 of the Labor Code shall not apply to shares issued by any foreign or domestic corporation to the following persons: