Are Supermajority Board Voting Bylaws Effective?

Section 204 of the California Corporations Code lists a number of possible provisions that may be included in the articles and "which shall not be effective unless expressly provided in the articles".  Included in this list of permissible provisions is the following:

"A provision requiring, for any or all corporate actions (except as provided in Section 303, subdivision (b) of Section 402.5, subdivision (c) of Section 708 and Section 1900) the vote of a larger proportion or of all of the shares of any class or series, or the vote or quorum for taking action of a larger proportion or of all of the directors, than is otherwise required by this division."

This would seem to render nugatory a bylaw provision imposing a super-majority vote requirement for director action.  However, the bylaws may effectively impose a higher board vote requirement to a limited extent.  How is this possible?  The penultimate sentence of the ultimate paragraph of Section 204(a) provides: "Notwithstanding this subdivision, bylaws may require for all or any actions by the board the affirmative vote of a majority of the authorized number of directors."