Some people may be too frail or have physical disabilities that prevent them from making a full signature. Providing the person is legally competent, the person may sign via a procedure known as signature by mark. To do this, the person makes a mark, such as an X, on the document, and two other people serve as witnesses that the person made the mark. The witnesses are only verifying that they witnessed the individual make his or her mark on the document. As with any signer, the person making the mark must be identified by the notary public through satisfactory evidence. A notary public is not required to identify the two persons who witnessed the signing by mark or to have the two witnesses sign the notary public’s journal, unless they are serving as credible witnesses for identification purposes.