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.
Note: If you reset numbering in Number Maintenance, it only renumbers new records. It leaves the numbering as-is for existing records in system tables.