A 30-cent Papal Arms postage stamp was overprinted on October 1, 1931, as a 25-cent (centissimi) provisional stamp. The overprint covered the rate for foreign postal cards and frequently used domestic rates. The overprint was affixed to the black/yellow stamp from the Conciliation issue, (Scott Number 5), originally issued August 1, 1929, the first set of postage stamps issued by Vatican City.
The 1931 red vermillion overprint consists of a "C" and "25" affixed to the lower portion of the design by the Vatican Polyglot Press (the Vatican-based printer established by Pope Sixtus V in 1587). The Press applied the overprint so as not to cover the Crossed Keys of St. Peter design of the Conciliation issue.
The Vatican withdrew the overprinted stamp from sale on February 28, 1947.
References:
Thomas I. Crimando, Introduction to the Postage Stamps of Vatican City, The Vatican Philatelic Society website, located at http://www.vaticanphilately.org/vc.htm, accessed August 6, 2010.
"Vatikanstaat," in Michel Europa Katalog, band 3, Südeuropa, Unterschleißheim, Germany: Schwanberger Verlag GMBH, 2008.
"Vatican City," in Stanley Gibbons Stamp Catalogue, part 8, Italy and Switzerland, 7th edition, Ringwood, Hampshire, England, 2010.
"Vatican City," in Scott Standard Stamp Catalogue, volume 6, Sidney, Ohio: Scott Publishing Company, 2006.
"Vatican Polyglot Press," located at http://www.gcatholic.com/dioceses/romancuria/d92.htm, accessed August 6, 2010.
