Lengthy description of the slew of bonuses given by a custom "Rugby Club" improvement:
"+2 Amenities and +1 Production. +1 Culture if 3 Rugby Clubs are present in your empire. +1 Culture from each adjacent City Centre, Neighbourhood, Pasture, and every two Farms. Additional bonus yields as you advance through the Civic tree. +10% combat experience to land units trained in this city.
Must be built on flat Grassland or Plains; may be built on Floodplains. Limit of one per city. Tiles with Rugby Clubs cannot be swapped."
The description fails to clarify extra effects like Gold adjacency bonuses; that the improvement adds Tourism equal to the gold yield on the tile; or that it also provides +0.5 Housing.
Civilopedia entry for the Digger, described as an "Australian and New Zealand unique Modern era unit that replaces Infantry."
Two entries sit under a section labelled 'Unique To': Australia is represented by a kangaroo, and New Zealand is represented by a silver fern.
My mod was WAY overengineered in its mechanics but I liked the premise. Sharing Australia's unique unit said ANZAC without saying ANZAC.
The problem was the essay you had to read to fathom the horrific terrain-and-adjacency-dependent Rugby Club. I've learnt my lesson, none of THAT ever again