It doesn't make sense to sign a minor injury or not. When we take a bath, the skin scratched by our fingers will have red marks, which also constitutes a minor injury, called subcutaneous soft tissue contusion. So there is no need to identify minor injuries at all. What needs to be identified is that the injury does not constitute a minor injury. Minor injuries are not graded, and it's the same if you scratch your arm red or break your head.

In criminal law, intentional injury requires that it constitutes a minor injury or more before criminal responsibility is taken.

In your case, you should judge the nature of both parties' actions according to legal evidence, not injury identification. Of course, if both sides ask for an injury appraisal, the police station will take the parties to a forensic expert appraisal, and I will sign the injury appraisal myself. Generally, the other party is not required to sign the appraisal results. It seems unnecessary for the police station to ask you to sign the other party's appraisal results.

In addition, if you don't admit that the other person hit someone in your own transcript, it doesn't mean that you caused it. Even if you sign the other party's appraisal conclusion, it doesn't mean you recognize yourself.

According to the law, you can refuse to sign any materials provided by the police station, including your own transcripts. The law also stipulates that if a party refuses to sign, it shall be signed by two or more police officers and explain that the party refuses to sign, and the materials also have legal effect.