Forever Stamps 在2007首度推出時 Forever Stamp Forever Stamp in the words of the US Postal Service Forever Stamps number of stamps Forever stamps Forever stamps "Forever Stamp" Forever Stamp Forever Forever Stamps Forever Stamps Forever Stamp Forever Stamps Forever Stamps Forever Stamp Forever Stamps Forever Stamps many stamps Forever Stamps Forever Stamps Forever Stamp Forever Stamp Forever Stamps Forever Stamp service calls them "non-denominational" postage Forever Stamps