Quidditch Fouls 
        Rules are of course "made to be broken." Seven hundred Quidditch fouls are listed in the Department of Magical Games and Sports records, and all of them are known to flave occurred during the final of the first ever World Cup in 1473. The full list of these fouls, however, has never been made available to the wizarding public. It is the Department's view that witches and wizards who see the list "might just get ideas.
        I was fortunate enough to gain access to the documents relating to these fouls while researching this book and can confirm that no public good can come of their publication. Ninety percent of the fouls listed are, in any case, impossible as long as the ban on using wands against the opposing team is upheld (this ban was imposed in I538): Of   remaining ten percent, it is safe to say that most would not occur to even the dirtiest player; for example, "setting fire to an opponent's broom tail," "attacking an opponent's broom with a club," "attacking an opponent with an axe."This is not to say that modern Quidditch players never break: rules. Ten common fouls are listed below. The correct Quidditch term for each foul is given in the first column. 

  Name              Applies to      Description 

Blagging All players
Seizing opponent's broom tail to slow or hinder 
Blatching All players Flying with intent to collide
Blurting All players
Locking broom handles with a view to steering opponent off course
Beaters only 
Hitting Bludger towards crowd, necessitating a halt of the game as officials rush to protect bystanders. Sometimes used by unscrupulous players to prevent an opposing Chaser scoring 
Cobbing All players
Excessive use of elbows towards opponents 
Keeper only
Sticking any portion of anatomy through goal hoop to punch Quaffle out.  The Keeper is suppose to block the goal hoop from the front rather than the rear
Chasers only
Hand still on Quaflle as it goes through goal hoop (Quaflle must be thrown)
Chasers only
Tampering with Quaflle, e.g., puncturing it so that it falls more quickly or zigzags
All players 
but Seeker
Any player other than Seeker touching or catching the Golden Snitch
Chasers only
More than one Chaser entering the scoring area
        Refireeing a Quidditch match was once a task for only the bravest witches and wizards. Zacharias Mumps tells us that a Norfolk referee called Cyprian Youdle died during a friendly match between local wizards in 1357.  The originator of the curse was never caught but is believed to have been a member of the crowd. While there have been no proven referee slayings since, there have been several incidences of broom - tampering over the centuries, the most - dangerous being the transformation of the referee's room into a Portkey, so that he or she is whisked away from the match halfway through and turns up months later in the Sahara Desert. The Department of Magical Games and Sports has issued strict guidelines on the security measures relating to players' brooms and these incidents are now, thankfully, extremely rare. 
        The effective Quidditch referee needs to be more than an expert flier. He or she has to watch the antics of fourteen players at once and the most common referee's injury is consequently neck strain. At professional matches the referee is  assisted by officials who stand around the boundaries of the pitch and ensure that neither players nor balls stray over the outer perimeter. 
        In Britain, Quidditch referees are selected by the Department of Magical Games and Sports. They have to take rigorous flying tests and an exacting written examination on the rules of Quidditch and prove, through a series of intensive trials, dut they will not jinx or curse offensive players even under severe pressure. 
This Information Came From 
Quidditch Through The Ages
by Kenniworthy Whisp