During this 10-year period, over 410 institutions have come to use the cataloging system. They include libraries at universities, junior colleges, and specialized high schools, governmental research libraries and prefectural libraries. NACSISŐs union catalog database is JapanŐs only union catalog for academic research libraries.
It took 7 years and 9 months to reach the grand total of 10 million records but a short period of just 2 years and 7 months to reach the 20-million record milestone. This achievement underscores the consolidation of the union catalog database and the unstinting efforts of all those concerned at participating institutions who have been dedicated to expanding the database.
The union catalog database not only alleviates the burden of cataloguing the work undertaken by the participating libraries by allowing each to share in the cataloging but it is also used as a holding information database to provide the most-up-to-date holdings through inter-library loan (ILL) systems.
Meanwhile, as with any institution which functions as a bibliographic utility, quality control over the rapidly growing number of records has been put forward as an issue to be tackled, and along with their work to integrate duplicate bibliographic records, twelve members of the Catalog Information Division are working on dispelling doubts and questions about the preparation of bibliographies raised by participating organizations.
The table below shows the input status before and after the 20-million record mark was reached.
| 19,999,996 | 11:20:54 | CD0193634233 | BN03818376 | FA002338 | Shinshu University |
| 19,999,996 | 11:20:54 | CD0193634459 | BN11514967 | FA004821 | Bunkyo University |
| 19,999,998 | 11:20:59 | CC0092885694 | BA18568190 | FA007284 | Sugiyama Jogakuen University |
| 19,999,999 | 11:21:00 | CD019363438X | BN00607862 | FA004060 | Kobe University of Commerce |
| 20,000,000 | 11:21:01 | CD0193634415 | BN13478933 | FA001787 | University of Tokyo |
| 20,000,000 | 11:21:01 | CC0092885628 | BA2629734X | FA008141 | Baika Women's College |
| 20,000,002 | 11:21:02 | CC009288564X | BA24349635 | FA008276 | Kobe Gakuin University |
| 20,000,002 | 11:21:02 | CC0092885672 | BA13819952 | FA007761 | Ryukoku University |
| 20,000,004 | 11:21:03 | CD0193634153 | BN02919345 | FA011769 | Faculty of Economics of University of Tokyo |
| 20,000,005 | 11:21:04 | CD0193634040 | BN08177949 | FA002972 | Hyogo University of Teacher Education |