Generally, a legal signature is a handwritten marking meant to identify an individual and affirm that she agrees with the terms of the document she is signing. Legal signatures are most commonly handwritten and may be printed, written in cursive or just a symbol. To be legal, a signature must be able to be attributed to an individual.
To be legal, a signature should be made without duress, threat or coercion.
In many circumstances, electronic signatures are considered legally binding. Electronic signatures often require verification of the signer's identity by asking for a Social Security Number or other identifying information.
An illiterate person may use an "X" or other simplified marking as a legal signature.
If someone is incapacitated or otherwise unable physically unable to sign a document, a third party may produce a legal signature on the injured party's behalf by signing the initial party's name and initialling it.
Many affidavits, consents and contracts must be executed in the presence of a notary public for the signature to be legal.