Appraisers "must be familiar with the local market" in which properties they are valuing are located, choose "appropriate comparable sales," and certify them as the homes "most similar" to the property being appraised, Freddie Mac said in a bulletin to lenders.The mortgage giant said new rules for appraisals don't require that appraisers select distressed properties -- including short sales, foreclosures or real estate-owned properties -- when identifying "comparable properties" for valuations."However, if the appraiser determines that these are representative of the properties available to typical purchasers for the market in which the property is located, appraisers must consider their use," Freddie Mac said.The bulletin, published Friday...