Cobbing is a Quidditch foul for “excessive use of elbows” (GF8, QA6).
All known fouls, including cobbing, were committed during the very first Quidditch World Cup of 1473 (QA6).
The Bulgarian team’s Keeper, Zograf, fouled Irish Chaser Mullet with his elbows during the 1994 Quidditch World Cup final between Bulgarian and Irish teams, causing referee Hassan Mostafa to award Ireland a penalty (GF8).
This cobbing incident was the subject of the discussion between Mr Weasley and Charlie in the campground after the match (GF9).
The English word "cobbing" has several meanings, including (1) blows to the buttocks in a military context and (2) inferior building materials or shoddy building work.
Lexicon list of Quidditch fouls
From the Web
Writing by J.K. Rowling on Pottermore: History of the Quidditch World Cup
Pottermore feature: Quidditch collection
Harry Potter Wiki:
Tags: attacks cheating fairness fouls match sportsmanship tactics team