Post bar is a way of reselling second-hand goods and a popular e-commerce model. ST is a very common word in sending photos, which stands for "physical store". In other words, when sending photos, merchants need to provide information about their physical stores, including addresses and contact information. In this way, buyers can buy second-hand goods with more confidence, because they know the actual location of the merchants and can contact them directly when needed.

ST has another meaning in the auction, that is, "private shop". Unlike physical stores, private stores are run by individuals, mainly because sellers auction second-hand items they don't use. This way is very convenient for individuals and can quickly realize idle items. But for buyers, it is necessary to pay more attention to the seller's evaluation and credibility to avoid fraud and other problems.

In order to protect the rights and interests of merchants and buyers, the auction platform will authenticate merchants' physical stores and audit private stores. In the authentication process, the auction platform will evaluate whether the merchant's physical store really exists, whether the facilities are complete and whether there is a legal qualification certificate. After approval, merchants or private shops can auction on the auction platform. In this way, buyers and merchants can conduct transactions with greater peace of mind and protect their own interests.