Signing by mark. Signing by the sign X which is the mark used when the signature of an illiterate
or physically incapacitated person is required. The name is written by some one else like this:
John X Doe. Then above the X is written "His" and below it is written ."mark.'' The illiterate person,
if able, makes the mark; in case of physical incapacity the mark is made for the signer, whose
fingers are pressed upon the penholder while the point of the pen rests upon the X. A signature by
mark is usually required to be verified by the signatures of two witnesses.