Orphaned pages block help

This block display a list of all pages that are'nt accessible from the wwwroot.'/help.php?module=wiki&file=index.html">index block'; ?> . Normally this pages exists because in some version of a page exist a link which is deleted in the current version.For example:

If one day you have a page called 'one' that have a link to 'two' and to, at it's time, have a link to 'three' and three has content:

one -> two -> three

If one day you reedit 'one' and delete the link to 'two', 'two' and 'three' won't be accessible any more from the index. Those pages will be orphaned:

one *broken link* two -> three

In this case, orphaned pages will display 'two' and 'three'.