User-defined structures would be more beneficial if we could do this sort of
thing:

%p/%[ID:::%n%q:%n%q].%t

So, structure variables to be parsed when they are inside the querystring
block.  Resulting filenames would be like (if my logic is correct):

/index.php?type=home
/folder/page.php?ID=1234
/folder/page.php?ID=5678&p=1
/folder/page.php?p=2

/indexABCD.html
/folder/1234.html
/folder/5678.html
/folder/pageEFGH.html