a <#cover> <#cancel=cancelled> on the day a stamp is issued, in the city in which it is released. Modern First Day Covers may actually be cancelled up to 30 days after the date of issue, and not necessarily in the city whose postmarks they bear. First Day Covers may be addressed or unaddressed, and with or without <#cachet=cachets>. See also <#unoffdc=Unofficial First Day Cover> and <#secondday=Second Day Cover>.