"Superscribed" is a word in ENGLISH

To direct in writing, as a letter; to superscribe, or to direct and transmit; as, he addressed a letter.

A blank paper, with a person's signature, etc., at the bottom, given to another person, with permission to superscribe what …

To put a direction or address upon; to mark with the name and residence of the person to whom anything …

To write or engrave (a name, address, inscription, or the like) on the top or surface; to write a name, …

of Superscribe

The act of superscribing.

Not addressed; not superscribed, as a letter.