Section 9--519. Numbering, Maintaining, and Indexing Records; Communicating Information Provided in Records. (a) Filing office duties. For each record filed in a filing office, the filing office shall: (1) assign a unique number to the filed record; (2) create a record that bears the number assigned to the filed record and the date and time of filing; (3) maintain the filed record for public inspection; and (4) index the filed record in accordance with subsections (c), (d), and (e). (b) File number. A file number must include a digit that: (1) is mathematically derived from or related to the other digits of the file number; and (2) aids the filing office in determining whether a number communicated as the file number includes a single-digit or transpositional error. (c) Indexing: general. Except as otherwise provided in subsections (d) and (e), the filing office shall: (1) index an initial financing statement according to the name of the debtor and index all filed records relating to the initial financing statement in a manner that associates with one another an initial financing statement and all filed records relating to the initial financing statement; and (2) index a record that provides a name of a debtor which was not previously provided in the financing statement to which the record relates also according to the name that was not previously provided. (d) Indexing: real-property-related financing statement. If a financing statement is filed as a fixture filing or covers as-extracted collateral, or timber to be cut, or a cooperative interest, the filing office shall index it: (1) under the names of the debtor and of each owner of record shown on the financing statement as if they were the mortgagors under a mortgage of the real property described; and (2) to the extent that the law of this state provides for indexing of records of mortgages under the name of the mortgagee, under the name of the secured party as if the secured party were the mortgagee thereunder, and; (3) if the real estate is in the City of New York or in Nassau, Onondaga, or any other county where the block system of recording or registering and indexing conveyances is in use, according to the block in which the real estate is situated; the filing officer may index such statements according to the names of the record owners of the real estate in a single consolidated index installed and maintained by him pursuant to section five hundred twenty-nine of the county law. (e) Indexing: real-property-related assignment. If a financing statement is filed as a fixture filing or covers as-extracted collateral, timber to be cut or a cooperative interest, the filing office shall index an assignment filed under Section 9--514(a) or an amendment filed under Section 9--514(b): (1) under the name of the assignor as grantor; and (2) to the extent that the law of this state provides for indexing a record of the assignment of a mortgage under the name of the assignee, under the name of the assignee; and (3) if the real estate is in the City of New York or in Nassau, Onondaga, or any other county where the block system ofrecording or registering and indexing conveyances is in use, according to the block in which the real estate is situated; the filing officer may index such assignments according to the names of the record owners of the real estate in a single consolidated index installed and maintained by him pursuant to section five hundred twenty-nine of the county law. (f) Retrieval and association capability. The filing office shall maintain a capability: (1) to retrieve a record by the name of the debtor and: (A) if the filing office is described in Section 9--501(a)(1), by the file number assigned to the initial financing statement to which the record relates and the date and time that the record was filed or recorded; or (B) if the filing office is described in Section 9--501(a)(2), by the file number assigned to the initial financing statement to which the record relates; and (2) to associate and retrieve with one another an initial financing statement and each filed record relating to the initial financing statement; and (3) if the real estate is in the City of New York or in Nassau, Onondaga, or any other county where the block system of recording or registering and indexing conveyances is in use, to retrieve a record according to the block in which the real estate is situated. (g) Removal of debtor's name. The filing office may not remove a debtor's name from the index until one year after the effectiveness of a financing statement naming the debtor lapses under Section 9--515 with respect to all secured parties of record. (h) Timeliness of filing office performance. The filing office shall perform the acts required by subsections (a) through (e) at the time and in the manner prescribed by filing-office rule, but not later than two business days after the filing office receives the record in question. (i) Inapplicability to real-property-related filing office. Subsections (b) and (h) do not apply to a filing office described in Section 9--501(a)(1).