April 25, 1929: the propaganda-charity issue "Philately for Children". Overprint applied with a hand stamp on USSR postage stamps. The stamps were in circulation for only one day. It had no real connection to philately and was produced under the influence of dealers in philatelic material.
The announced total print run of all stamps in the series—4,313 copies—obviously, due to its insignificance, could have had nothing to do with the declared goal of helping homeless children.
Moreover, 90% of the stamps (3,855 copies) ended up in the museum’s holdings; 485 stamps were found on postal items; and 34 pieces remained uncancelled in collectors’ hands.