When the backlinks module was introduced, it used the following syntax: api.php?action=query&list=backlinks&titles=Foo In July 2007, this was changed [1] to: api.php?action=query&list=backlinks&bltitle=Foo The first version was still supported for backwards compatibility, but threw a warning saying support would be removed soon. The 'soon' part wasn't exactly true (the warning was introduced 10 months ago), but it's really gonna happen now: titles= support for backlinks, embeddedin and imageusage has been discontinued as of r34518 [2]. This revision will go live on Wikimedia wikis some time in the next few days, and will be part of 1.13 and all later versions. Any client programs still relying on the old behavior should've been fixed a long time ago. Roan Kattouw (Catrope) [1] http://svn.wikimedia.org/viewvc/mediawiki?view=rev&revision=23774 [2] http://svn.wikimedia.org/viewvc/mediawiki?view=rev&revision=34518