Signing my daughter up for softball, I had to laugh at this (stripped down) Parents Code of Ethics:

• I will encourage good sportsmanship
• I will place the emotional and physical well-being of my child ahead of my personal desire to win.
• I will remember that the game is for the youth – not adults.

I guess they got sick of parents yelling and screaming and getting into fights!

UPDATE: I ended up being fairly obnoxious, myself, out there on the sidelines. You really do get caught up in it when it's your kid on the field.