On 2015-10-19 22:20, Christian Bruun-Ghalbia wrote:
It will not work on page Foo. It works in template namespace only (?). On page Foo it transclude "template:/TemplateData"
Hmm, I actually think the main namespace doesn't allow subpages by default, so that's probably the reason. See https://www.mediawiki.org/wiki/Manual:$wgNamespacesWithSubpages on how to enable them.