Does anyone know why…….

Comes from jeu de la poule

Pool has many meanings in English, including "a collection of things", in this case a collection of rugby teams.

You're probably often heard about pooling money together. It doesn't mean throwing wads of notes into a pond.

Blazers are a type of jacket often used by clubs and sporting organisations. I believe it comes from fox hunting, where the jackets are "blazing" red.

In Irish sports journalism "blazer" has become a disparaging synonym for sports officials, more associated with FAI officials these days I would have thought. The rugby equivalent is an "alickadoo".

The haka was once only done by touring All Black teams. It wasn't even taken seriously until the 1980s when Wayne Shelford decided that it was disrespectful to Maori culture unless it was done right. Most fans seem to like it so it became a fixture and opposition teams now have to obey certain restrictions while it is being preformed to prevent any potential mayhem.

The jackets worn by fox hunting horse riders (Hunts) are referred to as 'Pinks'