Additional objects.

Additional objects provide APIs to list choices, links between records, e-mail notification, creating charts and reports, and workspace for manipulating saved queries, charts, and reports.

Additional objects
Description
HookChoices object
Lists choices in a CHOICE-LIST hook
Link Object
Connects an original record (parent) with a duplicate (child) record
MailMsg Object
Supports an e-mail notification hook (OleMailMsg object for COM API, CQMailMsg object for Perl API).
CHARTMGR Object
Provides an interface for creating charts
ReportMgr Object
Provides an interface for generating reports
Workspace Object
Provides an interface for manipulating saved queries, reports, and charts

A Link object is a link between an original and a duplicate Entity. If you visualize the duplicate relationships as a tree with entities as the nodes, then links are the lines between the nodes.