Internal Links in the Same Window with [URL]

I was having trouble with a forum recently, trying to get one specific URL to open in the same window, instead of in a new window, using the [url]  [/url] code.

After ages I came across a simple solution [iurl] [/iurl]

I assume the i stands for internal.

I wonder if [eurl] would work on a site that forces all links to open internally ?  e = external