If you have defined a default document for a given IIS virtual directory, any link pointing to the directory will actually point to the default document for that directory. However, you should keep in mind that loading a page in this way requires two round-trips from the client to the server.
For example, say that you have the following link:
When the user clicks on this link, the browser will make a first request to the server, which will return the information that www.yourdomain.com/Articles is actually a directory, not a file. The browser will then add a slash to the URL and post a new request for www.yourdomain.com/Articles/. Only then IIS will reply by sending the client the default document for the Articles subdirectory, or by displaying the list of all the files in that directory, if directory browsing is enabled.
You can save the browser the first trip to the server by adding a slash to all directory names in you hyperlinks, as in:
Even better, unless you have some reasons not to do so, you should specify the exact name of the page you’re requesting: