When the California Public Employees Retirement System recently singled out six companies for its latest annual “Focus List” of businesses with poor corporate governance performance, five shared at least one fault: requiring a super-majority of votes to change bylaws or charters.

Brocade Communications, for example, requires a two-thirds majority for shareholders to amend its bylaws; Cardinal Health and Mellon Financial insist on three-fourths, while OfficeMax and Sovereign Bancorp as much as four-fifths for some changes.