N.Y. RPP Law § 316

§ 316. Indexes. Each recording officer must provide, at the expense of\nhis county, proper books for making general indexes of instruments\nrecorded in his office, and must form indexes therein, so as to afford\ncorrect and easy reference to the records in his office. There must be\none set of indexes for mortgages or securities in the nature of\nmortgages and assignments of rent; and another set for conveyances and\nother instruments not intended as such mortgages or securities, and\nexecutory contracts for sale, purchase or exchange of real property, or\nmemoranda thereof, and instruments canceling or extending such\ncontracts. Each set must contain two lists in alphabetical order, one\nconsisting of the names of the grantors or mortgagors and assignors,\nfollowed by the names of their grantees, mortgagees or assignees, and\nthe other list consisting of the names of the grantees or mortgagees and\nassignees, followed by the names of their grantors, mortgagors, or\nassignors, with proper blanks in each class of names, for subsequent\nentries, which entries must be made as instruments are delivered for\nrecord. This section, so far as relates to the preparation of new\nindexes, shall not apply to a county where the recording officer now has\ngeneral numerical indexes.\n A recording officer who records a conveyance of real property or\nassignment of rent, sold by virtue of an execution, or by a sheriff,\nreferee or other person, pursuant to a judgment, the granting clause\nwhereof states whose right, title or interest was sold, must insert in\nthe proper index, under the head, "grantors" or "assignors", the name of\nthe officer executing the conveyance, and of each person whose right,\ntitle or interest is so stated to have been sold.\n Such indexes shall form a part of the record of each instrument\nhereafter recorded.\n A county clerk may adopt a new indexing system utilizing\nelectro-mechanical, electronic or any other method he deems suitable for\nmaintaining the indexes.\n