Default cataloguing data entry sheet appears with all MARC-21 fields. This not convenient for fast cataloguing.
How to disable unwanted fields and retain commonly used MARC-21 fields.
Go Administration > MARC Bibliographic Framework
Download a model framework from here and save in your system.
Upload the sample framework. Click on Import button.
Selected fields have arranged in single tab. You can enable or disable more fields again by visiting
Administration > MARC Bibliographic Framework