XFileSharing Pro - 2 different styles with one link

[stamos]

somewhere here in the forum I saw from admin the link to test a new style before you are publishing it.
can someone remember that link?
something like
...site.com?op=style2

[admin]

http://yoursite.com/?design=2 (it will use files from /cgi-bin/Templates2).

[stamos]

that's it, thank you!