"They climbed a flight of stairs and entered the Creature-Induced Injuries corridor, where the second door on the right bore the words: 'Dangerous' Dai Llewellyn Ward: Serious Bites." (OP22)
"Saturday: Ballycastle Bats vs. Caerphilly Catapults, venue to be decided (Muggles camping on Ellis Moor. Contact Dept. of Magical Games and Sports, Ministry of Magic for details)." (DP4)
Welsh Quidditch team founded in 1402 (QA7).
Their most famous player 'Dangerous Dai' Llewellyn was eaten by a Chimaera in Mykonos, Greece. The player who takes the most exciting risks is now awarded the Dangerous Dai Commemorative Medal at the end of each season (QA7). Arthur Weasley's stay in St Mungo's is spent on the Dai Llewellyn Ward, which is located on the First Floor and specialises in treating dangerous bites and other creature-induced injuries (OP22).
The British record for fastest capture of a Snitch (three and a half seconds) was during a game against the Tutshill Tornados in 1921. Unfortunately this result was achieved against the Caerphilly Catapults (QA7).
They then lost to the Montrose Magpies after the Magpies had fired their Muggle-obsessed Chaser Alasdair Maddock (DP3) (the Catapults having won the previous season's fixture when Maddock had tried to "dribble" a quaffle) (DP1).
Caerphilly, a town in South Wales, lists a rugby football club but no Quidditch team appears in its Wikipedia entry (Wikipedia: Caerphilly).
Although the dates printed on the Daily Prophet Newsletters are DP1: 31 July 1998, DP2: 8 February 1999, DP3: 1 June 1999 and DP4: 1 October 1999, the timeframe for those events is 1992-1993.