The language in the preamble, though brief, marks the first time Microsoft has publicly acknowledged that it's willing to make a proxy fight out of its campaign to acquire Yahoo. To date, the company has declined comment on reports in the New York Times and other publications that such a campaign is in the cards. Microsoft may have little choice but to resort to a proxy fight as Yahoo's board has flat out rejected Microsoft's offer to buy the company outright for $31 per share. The board last week in a statement said the offer "substantially undervalues" Yahoo. To win a proxy fight, Microsoft would have to convince Yahoo shareholders to vote for a new board of directors that would be friendly to the transaction at Yahoo's next annual meeting -- most likely in May. A proxy war won't be cheap, however. Various estimates put the cost of directly soliciting Yahoo shareholders, and associated legal fees, at between $20 million and $30 million. It would, however, be less expensive than raising the buyout offer.