The Wizarding Supporters of Scottish Rugby Union (WSSRU) was an international organisation for witches and wizards who loved the Muggle Scottish rugby team. It was established by magical fans of Angus Buchanan, a Squib who played for the team and won the adoration of Muggles and wizards alike, shortly after his death on 27 July, 1927. Its members hailed from Scotland as well as many other countries around the world.
The group gathered the night before every match held between the Scottish rugby team and another country, toasting Angus's memory and eagerly anticipating the muddy, rough-and-tumble spectacle of Muggles facing off against each other on the field.
There were persistent rumours that the WSSRU's true goal was to secretly install a gifted Squib on every Scottish team. Players suspected of having been installed through the WSSRU's actions include Kelly Brown, Jim Hamilton, and Stuart Hogg (the latter was, indeed, a wizard).
- Pottermore (Mentioned only)