Article 77 The parties may modify the contract through consultation.
If you think there is something unclear in the agreement, you can negotiate with the other party to modify the content. Re-sign the gift agreement or modify the original contract for the unclear content, and indicate: both parties agree to this modification, and the date of modification shall be signed by both parties.
It is best not to unilaterally modify the signed contract, because it is impossible to determine whether the "unknown things" will change the basic content of the contract, directly affect the contractual rights and obligations of both parties, and may seriously lead to the invalidation of the contract.