A ClearCase hyperlink is not a URL or a URI. It's simply a double connected pointer between any two ClearCase objets. The fact that it's double connected means that both sides of the pointer - both objects - are aware of the existence of the hyperlink.
The hyperlinks are he foundation of the internal implementation of ClearCase. ClearCase hasn't got a relational database - anywhere -in it's internal architecture. Every relation is implemented through the use of hyperlinks. If this knowledge is exploited in the right way you can trace anything from anywhere.
If you know what you are looking for it's extremely effecient (and fun ;-) but if you want to search linear across all items or objects with nothing to go at ...it really sucks.