This page demonstrates the new parameters
If you have a very big number of pictures attached to a page, it may be better to split them to a number of subpages. You could do it by manually creating the pages and using the
count= parameter, but as of version 20081120, there is the
perpage= parameter which lets you automatically split the thumblist and a place link trail below it for easy access.
The split lists can be supercached too.
Note that this feature will be better used with only one thumblist in the page. (If there are more than one thimblists, and the number of their subpages is different, some thumblists may display nothing. See Perpage?page=16 where the number 16 is more than the existing subpages in 3 out of 4 thumblists.)