The law requires the contract to be signed by the party to be bound. The duplicate copies are customarily each signed by both parties. Signing may be by subscribing one's name or if unable to write, by marking. Any mark made with intention that it constitute signing is sufficient. Mere signing makes a valid contract. The seal, acknowledgment, and witnesses are not necessary.

It is advantageous to seal the instrument. It raises a presumption that the person who has affixed his seal received a consideration. It places the burden upon him of disproving it, should he desire to defeat the contract. Another advantage of sealing the contract is that when sealed, the obligations of the parties are kept alive by law for a greater length of time, the statute of limitations on sealed instruments being much longer than on instruments not under seal. The seal, however, has not the advantage of restricting the obligation to the one signing the contract. An undisclosed principal may, notwithstanding the seal, be held.

Witnessing the instrument accomplishes little. It is convenient as a memorandum of the fact that the witness was present and saw the parties sign.

No instrument can be recorded unless acknowledged or proven. While contracts are not usually recorded, nevertheless in exceptional cases, if fraud is suspected great harm may be avoided if the contract be placed on record and public notice of its terms so given. For this reason it is very often wise to have the contract acknowledged. This is done by the parties acknowledging their execution of the instrument, before an officer to whom they are known to be the persons executing the instrument and who is empowered by law to take acknowledgments. The officer then signs a certificate of acknowledgment upon the instrument. If the parties either cannot or will nor acknowledge the instrument, the fact may be proven by the witness, who swears before the proper officer that he was present and saw the parties sign the instrument, that he knew them to be the persons described in the paper. The officer then signs a certificate of these facts on the instrument, and it can be recorded. (Appendix forms 15 to 28.)