Another quick question :)
   Are the rules for creating a download url from the "file" tag in the
   rdf catalog consistent?
   let's say i have a html and zipped file, of #etext15560 , in this case
   the download link is
   &f;dirs/1/5/5/6/15560/15560-h.zip
   The way to recreate from the arguments is obvious (if lengthy), but i
   seem to recall it changed before - is there a algorithm that always
   gives a "valid" link, or should i just give up compressing this and
   include the link in my db?