Managing record numbering Records in tables can be numbered automatically. In the base system, several tables are numbered, including Incident, Problem, Change Request, and Knowledge. You can also use these numbers anywhere that script is present, for example to generate watermarks for emails. Administrators can manage record numbering by navigating to System Definition > Number Maintenance. The current number format for a table, including the prefix (such as INC for incidents or CHG for changes), is stored in a record on the Number [sys_number] table.Figure 1. Number table You can renumber auto-incremented tables that extend the task table or manage numbering with a database field named Number this field. For information about renumbering custom tables, see KB0538764: Renumbering auto-incrementated custom tables in the ServiceNow knowledge base. Auto-numbering records in a tableHow to set up numbering for a table.Prepare to left-pad number fields in custom tablesBefore you configure left padding of number fields on a custom table or a table that does not extend the task table, you must prepare business rules and script includes.Prevent numbering gapsBy default, numbers are generated every time a new record is created. When records are created but not saved, a gap in the numbering is created. You can prevent these numbering gaps by generating numbers only when records are saved.Enforcing unique numberingAlthough duplicate numbers are rare, numbering does not enforce uniqueness, by default.