Q.: Why the labels are not displayed for Item Flows in Internal Block Diagram (ibd) diagrams?
A.: It is intentionally designed not to display labels (conveyed items) in some cases in Internal Block Diagram (ibd) and other diagrams to avoid the negative impact on the diagram layouts. When the conveyed items are created in new or existing diagrams, they are displayed automatically throughout the diagrams and can be displaced.
For the information about how to display the conveyed items, see Setting an Information Flow.