Secret mark

under construction
A secret mark is a tiny design variation. It is intended either as:
 * a way to distinguish printings or printings from different printers.
 * a security feature for postal authorities to detect any postal forgeries.
 * A feature added to distinguish official reprints from original printings.

Secret marks are by definition quite small and will require you to use a magnifier to detect them. [[File:PRC lantern guide.png|thumb|center|550px|All values of the People's Republic of China 1949 lantern set have the same secret mark to separate reprints from originals. In the reprint (right), The small irregular white dot in the lower right part of the lantern is now attached to the decorative border.

[[Category:S]]