System control numbers are used internally by library automation systems to tie bibliographic records to order, invoice, pattern, check-in, holdings, item, authority, patron, and other records within a library's ILS. In Symphony, they must uniquely identify the bibliographic entity to prevent the related holdings from showing up in the display for the wrong title or a fine being charged to the wrong patron.
For this library, the true system control number in Sirsi is the catkey or ckey, which is reflected in the 918, as well as in auto-generated call numbers (XX+ckey) or item records.
Most MARC-based databases store their local control number in 001, as does OCLC. We should preserve the OCLC 001 number in records from that source, as it is the closest to a universal system control number that we have. These will have the prefix of "ocm" or "ocn", depending on whether it is an 8 or 9 digit number. eBook and serial records may also have vendor-supplied 001s, most notably from Serials Solutions (ssj or ssib), Yankee (ybp), and the major historical ebook collections such as EEBO, ECCO and Evans.
Historically, 001s that start with "tmp" were also retained, as they were GPO shipping list brief records from Marcive, our federal depository record vendor. Other numbers in the 001 were deleted (such as 001 from Library of Congress, Records imported from a SmartPort destination (Melvyl, PennState, etc) or alphanumeric codes), as they may not be unique within our system and might cause false matches on our catkeys.
The LC control (formerly "card") number (LCCN) is an accession-type number first instituted by LC to identify and organize their printed card sets. It consists of two or three reserved spaces used when there is an alphabetic code prefix to the number, followed by the year of cataloging (either a two digit or four digit number) and a 6 digit accession number. If there is no alpha prefix, then there should be 2 (for four digit years) or 3 (for two digit years) blanks before the numeric portion of the LCCN. Please retain these fields and their spacing.
The 035 is used to identify the system control number from the source database. The source should be prepended as a parenthetical prefix ("(OCoLC)". "(WaSeSS)", "(DLC)") to the control number itself. Of course, there are exceptions for particular record sets, such as Marcive Shipping List "tmp" numbers which lack any agency prefix. In the case of records derived from OCLC, the number from the 001 should also be reflected in the 035, with the qualifier "(OCoLC)" added in place of the alphabetic prefix (ocl, ocm, ocn). If there is an OCLC number in 001 and no matching 035, please create one, as it is the 035 that enables Endeca's "record rollup" feature in Searcb TRLN. If an existing 035 (OCoLC) includes the "ocm" or "ocn" prefix, please delete the alpha prefix. For the most part, 035 other than from OCLC, Serials Solutions (WaSeSS), or the Marcive tmp numbers can be ignored.
035 (DLC) 2005297896
035 (Sirsi) o99894791
Beginning in May 2019 - the 917 field will be used for MARCIVE record export & overlay. The 917 will contain the same number as the 918 field (catkey). However, we reserve the use of the 918 field for use in the discovery layer (Blacklight; TRLN discovery). To avoid any possible conflict, we'll use the 917 catkey field for MARCIVE record management
While Sirsi as a rule does not make its internal system control number visible, the NCSU Libraries decided that this number was the most consistent unique identifier within its records, and thus made it explicit in the 918. This field is indexed in both Sirsi and Endeca and allows for the generation of static URLs to pass searches to Endeca. Do not delete this field in existing records unless there are multiple identical 918s.
However, if you are copying an existing Sirsi record to create a new record in the system, you must delete the copied 918 in the child record so that a new unique number can be automatically generated.
If you end up with multiple conflicting 918s, the easiest way to determine which one is real is to create a new call number or item record.
The automatically-generated number preceding the hyphen in an item record, or the decimal point in an XX call number, is the catkey.
918 Field Timing
The 918 field is added to Sirsi bib records as part of the Endeca extract script at the top of the hour when cataloging updates are sent to Endeca. The nightly cataloging update extract makes a second pass and adds 918 fields to any records missing one. IT occasionally looks for records missing a 918 field and updates them (usually once a year).
As of May, 2019 most of the 919 fields will be removed as part of a MARCIVE retro clean up.
The DBCN was the system control number for records in our former DRA ILS prior to 2003. Post migration to Sirsi Symphony, this field had little utility, and was supplanted by the 918.