Auxiliary handstamp, UNKNOWN
Postal clerks use 'Pointing Hand' rubber stamps to endorse a mail piece returned to the sender. These auxiliary stamps explain why the item could not be delivered. This stamp's marking "UNKNOWN" indicates that an addressee was not at the address provided on a mail piece.
This style of marking device is typical of those used for this purpose between the 1930s and today. They are less common when a specific ZIP Code appears in the text.
The ZIP Code on this artifact, 10048, is no longer in use. It corresponds to the World Trade Center (WTC), and that ZIP code was destroyed by the terrorist attacks on September 11, 2001. This handstamp was collected from the WTC mail sorting station on the fourth floor of the Church Street Station Post Office, New York City. The stamp was last used on September 11, 2001.