Not having three marks is an illegal business crime.

A four-piece set usually refers to a bedding set, including sheets, quilt covers, pillowcases and mattress covers. The three standards refer to: product name and trademark, manufacturer name and address, and national standard number for product implementation. These signs are essential elements for complying with national laws and regulations. The lack of any one of them may be considered as non-compliance with the law.

Therefore, if the four-piece set does not have three labels, that is, it lacks the product name and trademark, the name and address of the manufacturer, and the national standard number of the product, it may constitute an illegal business crime. It is recommended to choose legal products with three labels when purchasing bedding to protect your own rights and interests.