Definition:
A class of mail (formerly called second-class) consisting of magazines, newspapers, or other publications formed of printed sheets that are issued at least four times a year at regular, specified intervals (frequency) from a "known office of publication." Periodicals usually must have a list of subscribers and/or requesters, as appropriate (The Mailroom Companion, May 1996.)
Used By:
Only publishers and registered news agents approved for periodicals mailing privileges.