Server Administration > Item Type Attributes > Setting Up Documents > Document Relationships
  
Document Relationships
The following three classes of relationships work with the Segment, Node, and Shared Item types to complete the document model:
Structural
The structural relationship constructs the tree hierarchy or document structure. Each parent in the hierarchy has one or more children. Conversely, each child only has one parent.
The structural relationship is between the Segment and the Node or the Node and another Node, and is called Contains/Contained By.
Couplet
The couplet relationship connects the Node(s) to the Shared Item. This relationship, in combination with the Reference Mode field, controls how content is versioned, branched, and reused within the document model.
The relationships between a Node and Shared Item are called References and Referenced By, respectively.
Trace
Trace relationships link document content to other content items for a specific purpose.
Users can create trace relationships between two items in the document model repository, for example, between a Requirement and a Test Case, or between a higher-level Requirement and a lower-level Requirement.
Trace relationships connect Nodes (not Shared Items) together. As an administrator, you can define which relationship fields act as trace fields between document content items.
To learn how users create Trace relationships, see your Windchill RV&S User documentation.