That is the regulation issued by the General Administration of Sports of China (GAS). According to CNN, the rule is made that "players of the national team and the U23 team are prohibited from having tattoos. Those who have tattoos must have them removed. In special cases, tattoos must be covered. during training and competition after obtaining the consent of the whole team".
In addition
this regulation also prohibits the dragon skull Chinese U20 team from summoning players with tattoos.
Currently, in the Chinese national team, there are many players with tattoos on their bodies. There are even many people tattooing in places that are easy to see. Typical of these is midfielder Zhang Linpeng, whose arms are full of tattoo details. In addition, he also has a tattoo on his neck.
Another case is midfielder Zhang Xizhe. This is not the first time that the tattoo of a Chinese player has become a topic of discussion. In 2018, it was reported that the Chinese Football Association (CFA) had issued an "unwritten law" prohibiting players from showing off tattoos.

After this information was available
in some matches of the Chinese team as well as in domestic tournaments, the players with tattoos tried to cover them up very carefully. Some people use bandages to cover body parts with tattoos. Some other players choose to wear long sleeves.
At the time, the CFA regulation was controversial. Chinese football fans have argued that tattooing does not affect the quality of the player. Some people even commented that the regulation had the opposite effect, affecting the team's results.
To make it easy to understand is the case of Zhang Linpeng mentioned above. He is a veteran defender of the Chinese national team. If Zhang is eliminated because of the tattoo, the defense of this team will be greatly affected.
The same is true of the recent
regulation issued by GAS. Immediately after it was cheap skull clothing published, the Chinese newspaper Sina published a very long article to talk about this issue. The general idea of the article is that the management of the player's tattoo is outdated and unnecessary.
Accordingly, the fact that the Chinese team did not have good results in the international arena for many years and could not win tickets to the World Cup after 2002 was a matter of expertise. As an example, the article said that in the world many tattooed players are still very successful like Lionel Messi, Sergio Ramos...