[Mediawiki-l] How to retrieve parent page name ?

[Frames Project]

Hello

in page http://meta.wikimedia.org/wiki/Help:Variable

all variables available are described using as example a fictitious page

"User:Anonymous user/sandbox/my page" 

I did not see there any variable able to retrieve the parent page name
of the current one, that is : "Anonymous user" why ?

Is there a trick to get this name from inside  
"User:Anonymous user/sandbox/my page" ?

Thanks

Francois Colonna