John Hancock (?.)

• OK
• X
• acceptance
• affirmance
• affirmation
• approbation
• approval
• authentication
• authorization
• autograph
• certification
• christcross
• cipher
• confirmation
• countermark
• countersign
• countersignature
• counterstamp
• cross
• device
• endorsement
• go-ahead
• green light
• hand
• imprimatur
• initials
• mark
• mark of signature
• monogram
• nod
• notarization
• okay
• permission
• ratification
• rubber stamp
• sanction
• seal
• sigil
• sign manual
• signature
• signet
• stamp
• stamp of approval
• subscription
• the nod
• validation
• visa
• vise
• warrant