VI.6 Function 1A

Function 1A processes input addresses and NAPs. When Function 1A is called using two work areas, it returns information in WA2 related to the tax lot and the building (if any) identified by the input data (see work area layouts in Appendix 2(MSW) and Appendix 13 (COW) . If the input address is a pseudo-address, a warning is issued with Reason Code ‘8’ or ‘9’.

See Chapter V for a general discussion of Geosupport address processing, much of which is applicable to Function 1A. In particular, the various combinations of data items that can be used to specify an input address are described in Chapter V.3. Chapter V.4 discusses how Function 1A differs from the other address-processing functions with respect to the validation significance of input address acceptance and rejection, and explains why Function 1A is the best address-processing function to use to validate addresses. Special address processing features discussed in Chapter V are also available with Function 1A, including duplicate address processing, the special Marble Hill/Rikers Island feature, and the special Ruby Street feature.

An important purpose of Function 1A is to provide the BBLs for which addresses are known. The BBLs can then be used (outside of the Geosupport System) to retrieve information from various city files that are keyed to BBL, including DOF’s billing address files, from which the name and mailing address of the party registered to receive real estate tax bills can be retrieved. This same party might also be an appropriate recipient for many other property-related city mailings, such as notices of inspections, violations, summonses, fines, hearing notifications and licenses.

If the property is part of a Business Improvement District (BID), the BID is returned in Work Area 2 as a borough and five-digit street code (B5SC). Function D may be used to obtain the name of the BID.

The latitude and longitude of the location are also returned by COW Function 1A. In addition, COW Function 1A returns the DCP Zoning Map number.

The long WA2 option (COW and MSW) as well as the Extended WA2 option (COW only) are available for Function 1A. Note that Extended WA2 is not valid if Long Work Area 2 is in effect. All three WA2s (viz. regular, long, and extended) for Function 1A contain a set of data organized into a list. The list in the regular WA2 and the Extended WA2 is a List of Geographic Identifiers (LGI). The LGI is intended to provide a comprehensive geographic profile of the tax lot by listing, so far as the information is known and space allows, all of the buildings the lot contains; all of the street addresses and non-addressable street frontages of each of those buildings; all of the vacant street frontages of the lot; and all NAPs associated with the lot. See the entry for the List of Geographic Identifiers in Appendix 3 for a detailed discussion of the contents of the LGI.

The LGI’s entries are ordered so that entries with non-empty BINs are listed first, grouped by BIN. If the input address is a real address, the first group of entries in the LGI consists of the entries for the BIN corresponding to the input address, and (except for certain special cases) the very first entry is an address range encompassing the input address. (The special cases are when the input information contains the alternative borough for a Marble Hill or Rikers Island location or the alternative street name or street code for a Ruby Street address -- see Chapters V.7 and V.8. Any entries with empty BINs (a.k.a. zero BINs), such as entries for pseudo-address ranges, are listed after the entries with non-empty BINs as space in the LGI allows. If the input address is a pseudo-address, an address range encompassing it may or may not appear in the LGI, depending on the availability of space in the LGI and on the order in which the non-BIN entries happen to be listed.

The LGI has a maximum capacity of 21 entries, which for almost all tax lots is sufficient to contain all of the lot’s geographic identifiers. A tax lot that does have more than 21 geographic identifiers is said to have the ‘LGI overflow condition’. The LGI overflow condition is indicated by a value in the LGI Overflow Flag in Function 1A’s regular WA2, as well as by the issuance of a warning (Reason Code ‘A’).

By definition, when a tax lot has the LGI overflow condition, some of the lot’s geographic identifiers are not included in the LGI. In particular, it is possible that the BINs of some of the lot’s buildings do not appear in the LGI. The purpose of the long WA2 option for Function 1A is to provide a means for applications to retrieve a complete list of BINs for all the buildings on a tax lot, even for lots that have the LGI overflow condition. The long WA2 contains a List of Buildings on the Tax Lot. Each entry in this list consists only of a BIN; the list includes no address, street frontage or NAP information. (Such information can be obtained for each of the lot’s buildings by making Function BN calls.) The maximum capacity of the List of Buildings is 2,500, which is sufficient to list the BINs of all of the buildings on any tax lot in New York City.

Applications can use the long WA2 option for all tax lots, even for those that do not have the LGI overflow condition. Using the long WA2 option for every Function 1A call, rather than only for tax lots that have the LGI overflow condition, may be advantageous in applications that require a list of BINs but do not require the other information returned in the LGI. Doing so simplifies application design: only a single Function 1A call would be required for each input address, and the List of BINs, unlike the LGI, contains every BIN for the lot without repetition. However, users should be aware that, for tax lots that have the LGI overflow condition, a long WA2 call causes Function 1A to perform more I/O operations than a regular WA2 call.

If the input address to a Function 1A call (using the regular WA2, the long WA2, or the Extended WA2), is that of a condominium, Geosupport returns a ‘C’ in the Condominium Flag in WA2. In addition, the following information is returned for condominiums:

Condominium Billing BBL (or the billing BBL of the portion of the condominium in the tax block containing the input address, if the condominium is in more than one tax block). In some instances there may be a condominium that has not yet been assigned a Billing BBL by DOF (or the Billing BBL was not yet available when the Geosupport data files were generated); in these cases the BBL that is returned by Geosupport is set to zero and a warning message issued.
DOF Condominium Identification Number (provided that DOF has assigned an ID number to the condominium and GSS has entered it into the Geosupport data).
The low BBL of all the condominium units in the building identified by the input address.
The high BBL of all the condominium units in the building identified by the input address. For the positions of these fields in Work Area 2, see Appendix 2 and Appendix 13 for MSW and COW respectively.

Function 1A Extended Work Area 2 (Mode Switch set to ‘X’). This option is available in COW only. The first 246 bytes of the Extended Work Area 2 for Function 1A, up to the “Number of Entries in List of Geographic Identifiers” field, are the same as with regular COW Work Area 2. Aside from adding some filler and the new Function 1A Reason Code, Warning Code, and GRC fields (which are identical to the WA1 fields) to the work area for Function 1A Extended, the only change is in the address list. The street codes in the address list are B7SCs instead of B5SCs. The Principal Street Name (based on the B7SC in the address list) has been added to each element in the address list for the user’s convenience. Note that Mode Switch of “X” is not valid with the Long Work Area 2 Flag set to Y, since the Function 1A Long Work Area 2 primarily returns BINs, not street codes.