Adding Links to Detailing Symbols
After you have created links in a link set, they are available to attach to detailing symbols in the open DGN file. This allows you to click the detailing symbol and open the file that is linked to it. Links can be added to the following types of detailing symbols: section callouts, detail callouts, elevation callouts, plan callouts, drawing boundaries, and title text. For information about adding links to detailing symbols, see Adding Links to Elements.
Once a link is added to a detailing symbol, when you position your pointer on the detailing symbol you see an icon to create drawing. You also can see information about a detailing symbol's link on the Links tab in the Properties dialog.
If you no longer want the linked file to be attached to the detailing symbol, you can delete the link.