1. First of all, I don't think there are any hard and fast legal provisions, so we should sign it according to your contract requirements. If there are no requirements in the contract, it depends on whether there are provisions in the bidding documents/bidding documents. If there is, it should be implemented. If there is no regulation, you, Party A and the supervisor need to confirm who will sign it, and then supplement the contract to clarify the format and signer. Similarly, in general, all kinds of signature documents should be attached to the contract as attachments, and the signatory should sign according to that format and requirements. If there is no corresponding document attachment after the contract, it shall be in the format specified in the tender documents/bidding documents or the requirements of the signatory. However, in the process of contract execution, if there is any format modification or signatory modification, the contract should be supplemented and modified. As you said, if the information is complete and the supervisor seals it, it will only be a little troublesome if Party A has doubts. According to the document, change the stamped page, re-sign, and ask the supervisor to re-stamp. Don't be afraid of trouble. After all, Party A is the owner, and it is stipulated in the document. We have encountered too many such situations, not to mention the regulations, that is, both parties have sealed it, and it is possible to modify it, and the plan can't keep up with the changes.