Reversal of part of an order granting respondents' cross-motion for summary judgment, that: 1) the clerk may refuse to record petitioner's assignment and discharge as those instruments violate the "factual mandates" of section 321(3) of the Real Property Law; and 2) there is no valid distinction between MERS mortgages and MERS assignments and discharges for purposes of recording and indexing, is affirmed.