Related Documents
In the Document Edit screen, you may select the Related Documents tab which will enable you to related documents to each other.
Simply select the document that is related to the current document in the document editor and then click assign.
This action will automatically assign the current document to the related document also. Document relationship links do not break if a document is moved. The links are persistent until the relationship is removed.
To remove a related document, simply click the Delete icon from the related document list. This action will also remove the relationship from the previously related document also.