[MediaWiki-l] linking local .pdf files

[JFC Morfin]

I would like to link local .pdf files without having to use the 
[http://wiki./xxxx.pdf] format, so I can port a page and its related 
files to another wiki site. I read somewhere that a [media:xxxx] 
solution could exist but the information I can parse throughout the 
manuals is uncomplete and confuse. Is there an URL where this is 
explained or would someone be kind enough to explain it in simple 
working words?
Deep, deep thanks.
jfc