This is a notice from Albirex Niigata.
 

【Please note】
At Albirex Niigata, bringing and using musical instruments (such as trumpets, barca horns, vuvuzelas, etc.) and bringing and using step ladders are prohibited. Please check the following items in advance.
 

To all visiting supporters:
http://www.albirex.co.jp/guide/visitor.html

＜Spectator Etiquette and Prohibited Items＞
http://www.albirex.co.jp/guide/manner.html