4A stands for American Association of Advertising Agencies. 4A Association has strict standards for its member companies, and all 4A advertising companies are large-scale comprehensive multinational advertising companies.

At present, domestic 4A companies include Bodaqiao International Advertising Media Co., Ltd., Shi Sheng Great Wall International Advertising Co., Ltd., McCann Guangming Advertising Co., Ltd., Zhiwei Tangxun Zhongqiao Advertising Co., Ltd., Shanghai Ogilvy Advertising Co., Ltd., Shanghai Lingshi Advertising Company, Shanghai Darbys Advertising Company, Shanghai Jingxin Advertising Company, etc.

Other meaning:

4A (anyone, anytime, anywhere, anything): a way of lifelong education, mainly distance education.

4A, a yo-yo pattern. Also known as OS (rope-off) or rope-off technology. When playing, the rope is wound around the bearing first, and then the rope leaves the shaft at the moment of throwing it, and the bearing will rotate by itself, and then catch the ball in the air. At first glance, it looks like diabolo, but it's totally different. There are also many off-line exclusive tricks that diabolo can't complete.