Enterprise Administration > Implementing Windchill ESI > Implementing Windchill ESI in an SAP Environment > XML Schemas > Common Business Object (CBO) > Common Business Object Schema: Object Header > BOM Schema > CN Schema
  
CN Schema
The following describes the elements contained in the CN schema.
Element
Description
ObjectHeader
The system information for the current object. For more information, see Common Business Object Schema: Object Header.
WCID
Unique identifier for the CN; internal to Windchill PDMLink.
ChangeNumber
The CN identifier in the distribution target.
Description
Text describing the change.
ReasonForChange
Text describing the reason for the change.
ECNUserArea
Optional. Stores all user-defined data used for customization.