This feature will allow any jsp in the portal that is:
a) defined as "portlet_content" of a tile in tiles-defs.xml (or tiles-defs-ext.xml)
b) is invoked via the <liferay-util:include/> tag
to be overloaded on a theme basis (different on every page or community using a different theme, if applied).
The pattern will require that within the theme's templates folder the complete path to the original JSP be maintained with the file extension replaced to match that of the theme's chosen template language.
e.g. This would overload the original A) using the Velocity template language B) in the "classic" theme:
(or in following the merge technique used by themes, in: