Is the crawler a linkbase?

Links are stored in a link database. This is a simple flat file system with one record per link. Each record associates a link message with a dispatch message. When the linker receives a follow link action, it attempts to match the rest of the message with a link message in the database. The way this match is performed is dependant on information entered at the time the links were created about how specific or general the link is. If a match is found, then the dispatch message is sent back to the Document Control System. It contains the name of the target document and offset into it where the link was directed. This information is used to start up a Document Viewer of the appropriate type, load the target document, and move to the specified location. In this instance, the user is not aware of the operation of the Document Control System at all. As far as they are concerned they have asked to follow a link and the new document has appeared in another window.

Check MICROCOSM: An Open Model for Hypermedia With Dynamic Linking !