Suppose a company is asking its shareholders to approve a proposal, with one vote per share. Suppose I own 1000 shares. Can I use 600 shares to vote for the proposal, and use the remaining 400 shares to vote against it? Or must I use all my 1000 shares to vote for one side only? If this is the case, how do custodian and nominee companies vote on behalf of the real owners of the shares, if the custodian/nominee company holds shares for multiple clients who want to vote differently?