Oracle Forms

Link Type	When is this type of link created?
Use (U)	This type is generically used to describe an interaction between two objects. For example: between a Form Module and its Menu Module
Call (C)	A link of this type is created from a (popup) menu item invoking a menu to the cascading (popup) menu. For example: Between a data block item and the sequence specified in its Initial Value property. Between a Form Module and the Report Modules via Report Objects.
Inherit (I)	A link of this type is created from an object created by subclassing to the source object. It is also created between an object and its property class and between a subclassed Module and its reference modules.
Match (X)	This type of link indicates a link you have created using a Reference Pattern.
Rely On	This type of link is created between a data block and the server objects used to construct it.
Access	This type of link is created when there is a reference in the code to a data block item through host variable syntax (:block.item or :item).
Monitor	This type of link is created between a data block relation and the data block.

Oracle Reports

Link Type	When is this type of link created?
Rely On	from Oracle Report Data Link to child column from parent column to Oracle Report Data Link from group to query from query to PL/SQL code (function, procedure, package) from database column to query