A system may include a database disposed within a remote network management platform, a server device disposed in the platform, and a client device. The database may contain representations of configuration items, such as computing devices and software applications associated with the managed network. The server device may provide a graphical user interface including a sequence of panes to the client device. The sequence of panes may include an identifier pane, an identification rules pane, and a reconciliation pane. Each pane may include data entry fields that are operable to define a new class of configuration item. The server device may receive, by way of the graphical user interface, a definition of the new class that uniquely identifies configuration items of a particular type using at least the attributes. The server may store, in the database, the definition of the new class.