What it is:
An X-mark signature is a mark made by a person who is not able to sign his or her name.
How it works/Example:
Let's say John Doe suffers a traumatic brain injury and can no longer read or write. He marries his high school sweetheart and must sign the marriage certificate. Because he cannot write, he makes a mark in the shape of an X as his signature.
Why it matters:
The X-mark signature is a way for a disabled or illiterate person to mark his or her consent on legal forms. There is no law requiring a person's signature to look a certain way or include certain elements. However, because they are easily forged, X-mark signatures may not stand as appropriate consent in some courts.