Record number field type 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. Records in tables can be numbered automatically. 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. Add auto-numbering records in a tableYou can define one number format per table in the system.Prevent numbering gapsBy default, numbers are generated every time a new record is created. Enforcing unique numberingAlthough duplicate numbers are rare, numbering does not enforce uniqueness, by default.