From the README.txt of the Collection extension:
*$wgCollectionLicenseURL (string or null)*
HTTP URL of an article containing the full license text in wikitext format
for articles in this MediaWiki. E.g.
$wgCollectionLicenseURL = 'http://en.wikipedia.org/w/index.php?title=Wikipedia:Text_of_the_GNU_Free_Documentation_License&action=raw';
for the GFDL.
If set to null, the standard MediaWiki variables $wgRightsPage,
$wgRightsUrl and $wgRightsText are used for license information.
If your MediaWiki contains articles with different licenses, make sure
that each article contains the name of the license and set $wgCollectionLicenseURL
to an article that contains all needed licenses.
-- Johannes
This is strange: It works for me here.
Do you use a current version of the Collection extension?
If you enter the above URL in your browser, do you get the wikitext back?
Does anyone else have this problem and can give hints?
> So, I am expecting the copyright info would be added to the last page
> (or the first page) of the downloaded PDF book, but I can't see it at
> all.
Yes, the license should be at the end of the PDF.
> Is it because that I am using the public render server?
No, as long as your wiki is accessible from the render server (and it must be if you get PDFs back), this should make no difference.
> Or, do I need to add more global variables (e.g. $wgRightsPage,
> $wgRightsUrl and $wgRightsText) to the LocalSettings.php file? If yes,
> what values should they be?
No, setting $wgCollectionLicenseURL should be sufficient.
> Or, do I need to mark each wiki page somewhere which is licensed?
No. This is only needed if you use different licenses for different articles.
> Or, do I need to recofigure the entire MediaWiki site for some kind of
> license method?
No. Shouldn’t be needed.
-- Johannes