C:\?\myfolder - what does ? stand for

when I do a scan of my HDD , I get entries like C:\?\myfolder\myfile.gif

and when I recover it , it goes to "unknown folder"\myfolder\myfile.gif ..

what is the condition for recuva to put in a '?' instead of the correct folder name ?

if I am not clear .. you can look at the screenshot on the recuva site .

http://www.recuva.com/screenshots/screenshot-2---results

:unsure: