Fingerprint, legally called fingerprint, is more common in criminal proceedings.

In civil legal affairs, some people ask the other party to hold hands in the traditional way, which is equivalent to a clause in the contract, as long as both parties agree, but the law does not stipulate that this must be done.

In my opinion, if the other party to the contract has this requirement, as long as it is not a unilateral requirement, it is acceptable, and there is no so-called insult problem.