A system comprising: a database included within a remote network management platform, wherein the database contains representations of configuration items associated with a managed network, wherein the configuration items represent at least computing devices and software applications included within the managed network; and a server device included within the remote network management platform, wherein the server device is configured to (i) provide a graphical user interface including a sequence of panes, (ii) receive, by way of the graphical user interface, a definition of a new class that uniquely identifies configuration items of a particular type, and (iii) store, in the database, the definition of the new class, wherein the server device does not store the definition into the database until each pane of the sequence of panes has received required inputs, wherein an identifier pane of the sequence of panes includes first data entry fields for specification of an identifier of the new class, wherein an identification rules pane of the sequence of panes includes second data entry fields for specification of configuration item attributes that are operable to uniquely identify configuration items of the new class, wherein a reconciliation pane of the sequence of panes includes: third data entry fields for specification of authoritative devices; and fourth data entry fields for specification of a relative priority between the authoritative devices, wherein the authoritative devices are permitted to modify, within the database, one or more configuration item attributes of configuration items of the new class based at least in part on the relative priority, with a lower priority authoritative device able to modify a configuration item attribute until a higher priority authoritative device modifies the configuration item attribute, after which further modification of the configuration attribute by the lower priority authoritative device is prevented, and wherein the identifier pane appears before the identification rules pane in the sequence of panes, and wherein the identification rules pane appears before the reconciliation pane in the sequence of panes. a database included within a remote network management platform, wherein the database contains representations of configuration items associated with a managed network, wherein the configuration items represent at least computing devices and software applications included within the managed network; and a server device included within the remote network management platform, wherein the server device is configured to (i) provide a graphical user interface including a sequence of panes, (ii) receive, by way of the graphical user interface, a definition of a new class that uniquely identifies configuration items of a particular type, and (iii) store, in the database, the definition of the new class, wherein the server device does not store the definition into the database until each pane of the sequence of panes has received required inputs, wherein an identifier pane of the sequence of panes includes first data entry fields for specification of an identifier of the new class, wherein an identification rules pane of the sequence of panes includes second data entry fields for specification of configuration item attributes that are operable to uniquely identify configuration items of the new class, wherein a reconciliation pane of the sequence of panes includes: third data entry fields for specification of authoritative devices; and fourth data entry fields for specification of a relative priority between the authoritative devices, wherein the authoritative devices are permitted to modify, within the database, one or more configuration item attributes of configuration items of the new class based at least in part on the relative priority, with a lower priority authoritative device able to modify a configuration item attribute until a higher priority authoritative device modifies the configuration item attribute, after which further modification of the configuration attribute by the lower priority authoritative device is prevented, and wherein the identifier pane appears before the identification rules pane in the sequence of panes, and wherein the identification rules pane appears before the reconciliation pane in the sequence of panes. third data entry fields for specification of authoritative devices; and fourth data entry fields for specification of a relative priority between the authoritative devices, wherein the authoritative devices are permitted to modify, within the database, one or more configuration item attributes of configuration items of the new class based at least in part on the relative priority, with a lower priority authoritative device able to modify a configuration item attribute until a higher priority authoritative device modifies the configuration item attribute, after which further modification of the configuration attribute by the lower priority authoritative device is prevented, and wherein the identifier pane appears before the identification rules pane in the sequence of panes, and wherein the identification rules pane appears before the reconciliation pane in the sequence of panes.