To open the Path Browser on the <CatalogEntry> protocol, follow these steps:
The leftmost pane of the Path Browser shows the starting point of the
navigation (the <CatalogEntry> protocol). Each successive
pane shows a navigation from the previous pane, as indicated by the selection
in the drop-down list. The default navigation for a protocol,
Contents, appears in the second pane.
We can now use the Path Browser to browse the attributes and message specifications of the <CatalogEntry> protocol, and make the changes we need to make.