Water sign is a kind of billboard, commonly known as "water sign", which is often used to inform and guide people in meetings, exhibitions and weddings. Water brand has various materials and rich shapes, and is generally customized according to the place of use. For example, wedding water cards generally use festive and bright colors, while meeting water cards use conventional square cards, typical solemn colors and so on. It depends on the venue. There is no exact number, usually between one and two digits.