Why Are Many Masonic Tokens Marked "One Penny"?

I recently put up a batch of Masonic coins or tokens for sale on eBay, among them being a couple which in addition to other Masonic markings were engraved "One Penny." There were also two actual U.S. pennies marked with Masonic emblem and punched. Though I haven't gone deeply into it, I would guess that the penny is a traditional vehicle for identification of "brothers." It seems to have come about when a Masonic penny was minted as genuine coinage and circulated throughout the British Empire. Some information on the matter may be found here.