Cachet - a printed, embossed, or hand struck inscription, with or without illustration, impressed usually on the left side of an envelope face or postal packet to advertise the special circumstances under which the item was mailed, perhaps first or last day of issue, first flight, or any other commemorative situation. Cachets can be produced by the postal administration or by private parties and applied independent of postal authority.
Cancel - marks applied to stamps which prevent reuse. The marks often include a date, rate, route, or place of mailing.
Carriers' stamp - stamps used for mail delivery by private carrier from a post office to an individual addressee, particularly during the period 1842-60. When the postal service was first organized, letters were carried from post office to post office since there was no delivery to individual addressees.
Cash on Delivery (COD) Service - mail which collects the cost of postage and the product enclosed is collected from the recipient and forwarded to the mailer. This service is sometimes called 'Cash on Delivery'. Collect on Delivery (COD) service was introduced on July 1, 1913. Parcel Post Service, finally made available to U.S. citizens on January 1, 1913, was received with enormous enthusiasm. Farm families could use it to convey produce at standardized, understandable and lower rates than they had received from express companies. Marketers were thrilled with the promise of this new sales frontier. The growth of Parcel Post service was phenomenal. During the first six months of operation approximately 300 million parcels were handled. When Collect on Delivery (COD) Service was introduced seven months later, the popularity of parcel post went through the roof as mail order companies' profits exploded. COD and Parcel Post Service pushed the development of industry tied to the creation and development of unique parcel mailing containers, including those built to hold eggs by the dozens.
Certified Mail - a mail service that provides the individual sending a piece of mail with a receipt when the item enters the mail stream. It also provides a record of delivery when it reaches the final post office for dispatch to recipient
Certified mail stamp - a stamp paying for proof of delivery of first-class mail for which no indemnity value is claimed. Using this is a less expensive, less secure alternative to registered mail.
Charity seal - stamp-like label that is not a postage stamp and is distributed by a charity. They are often affixed to envelopes. Christmas seals are one example.
CIA invert - term applied to a U.S. stamp featuring a candlestick holder that was found upside down by CIA employees when buying stamps at their local USPS post office
Cigarette tube stamp - tax receipt paid on hollow tubes of cigarette paper to which small mouthpieces were attached, for those who made their own cigarettes, 1919-1933
Circular delivery stamp - local stamp issued in Great Britain (1865-67) by private companies for the delivery of circulars, sample packets, and other printed matter at rates which undercut the Post Office. A subsequent lawsuit disallowed the practice, but Post Office rates were lowered in 1870.
Citizens' Stamp Advisory Committee - the committee (also known as SeeSac for its initials - SCAC) that determines final stamp selection for the U.S. Postal Service. The fifteen committee members are selected by the postmaster general and typically include individuals whose backgrounds include educational, artistic, historical, and professional expertise. In addition to selecting stop topics, the committee also reviews and guides stamp designs.
City Delivery Service - a free mail delivery service, initiated on July 1, 1863, which was limited to northern cities with populations over 20,000. The service was a tremendous success, and by 1869 revenues from City Free Delivery superseded costs ten times over. After 1887, the department opened the service to areas with either populations exceeding 10,000 or postal revenues in excess of $10,000. City carriers used a variety of methods to get their patrons attention, from ringing twice (yes, the postman did ring twice), to whistles and even wooden door knockers that helped save wear and tear on carriers' knuckles.
City Free Delivery Service - a form of mail service available prior to 1863. Many large post offices had letter carriers, but they weren't paid by the government. They earned their wages by charging recipients one or two cents for each delivered letter. Most people saved their money and picked up their own mail. When Free City Delivery Service began on July 1, 1863, it was limited to forty-nine Northern offices, using four hundred and fifty letter carriers. The service was a tremendous success and by 1869 revenues from City Free Delivery were over ten times its cost. Until 1887, the Post Office Department stipulated that only cities with populations in excess of 20,000 were eligible for free delivery. After 1887, the department opened the service up to areas with either populations exceeding 10,000, or postal revenues in excess of $10,000.
Civil War patriotic covers - envelopes bearing expressions of patriotism, be they for the North or the Confederacy, such as flags, cannons, leaders, soldiers, and other wartime themes
Classification schemes—mail - a means of organizing mail. On March 3, 1863, the Post Office Department began to classify mail into three levels. The levels differed in cost, and over the years, processing techniques. Letters were first-class mail. Regularly issued publications were second-class mail. All other mail pieces were placed in the third-class mail category.
Classification schemes—post offices - a means of defining post offices. In 1864, post offices were divided into classes, determined by each office’s receipts and mail volume. Fourth-class offices were usually small units located on private property. First-class post offices were typically large and government-owned buildings.
Clean-cut perforation - the normal state of perforations from a perforating machine using sharp pins
Coil stamp - stamps processed in a single row and prepared for sale in rolls, often for dispensing from stamp vending and affixing machines. Some coils, including most U.S. coils, have a straight edge on two parallel sides and perforations on the remaining two parallel sides. Some coils are backprinted with sequence or counting numbers.
College stamp - stamps issued by the British universities of Oxford and Cambridge, which were officially granted the right to issue their own stamps for internal messenger service in the mid-1600s. Several other colleges used their own stamps between 1871 and 1886.
Collotype - a process utilizing a thin film of gelatin on the plate surface
Color missing - usually denotes an error in the printing process. It might be a completely missing step or the accidental stoppage of ink in a fountain on a multicolor press.
Color separation - a printing process using different colors from different plates, partially superimposed and blended to give a harmonious effect
Colored line roulette - perforations indicated by colored dashes printed over the top of the slits, used on stamps of Thurn and Taxis
Comb perforation - perforation produced by a machine which has the pins so arranged that they perforate three or more sides of each stamp in one complete row at a single stroke. One hole at each corner of each stamp is common to both the horizontal and the vertical row.
Commemorative stamp - a stamp printed in a limited quantity and available for purchase for a limited time. The design might note an anniversary associated with an individual, an historic event, or a national landmark.
Compound perforations - perforations that consist of two or more gauges per stamp. These usually consist of one gauge horizontally and a different one vertically. The horizontal gauge is written first and the vertical last (12 x 8). Mixed compound perforations are written clockwise starting with the top of the stamp (9 1/2 x 12 1/2 x 12 1/2 x 6 1/2).
Concessionary parcel stamp - stamps used by private firms at rates lower than government services
Confederate handstamps - the first Confederate stamps, which were lithographed, non-perforated five-cent sheets printed by Hoyer & Ludwig. They became available in October 1861. The 'stampless period', which refers to the six-month period before Confederate stamps were issued, forced Southern postmasters to develop a temporary system to replace this commodity. By creating provisional stamps or handstamps, postmasters were able to continue mail service in absence of a government issued postage stamp.
Confederate semi-official envelope - imprinted envelopes provided to departments within the Confederate government, though not everyone was granted franking privileges. 'Semi-official' envelopes, like the example shown here, required prepayment of postage in stamps.
Constitutional Post - post office established by Congress in 1775
Consular service fee stamp - stamps affixed to documents showing payment of specific fees for various duties of consular officers
Control number - numbers printed on backs of stamp that denote the year of printing. Control letters serve as indices for accounting records.
Cordials and wines stamp - stamp indicating collection of tax on such products
Counterfeit - an item, usually a replica of an existing stamp, made to defraud collectors. The term can also be applied to overprints, postmarks, etc. One of the most commonly found Confederate counterfeits is a complete set of counterfeit Confederate general issues, which was made up and marketed by a dealer in Springfield, Massachusetts. They are thus known as 'Springfield Facsimiles'. Crudely fashioned woodcut counterfeits have been made and printed of each of the Confederate general issues by several different counterfeiters, but few, if any, would deceive even the most novice collector. Many of these crude counterfeits were made in the 1870s, when there was a ready market for them as space fillers. There was little intent to defraud contemporary collectors. Also in this category are items termed 'bogus', which never existed in the presented format, bearing names of imaginary or existing postal authorities or services. These were created to fool or defraud collectors. There are numerous of these items among Confederate postmaster provisionals. They are also often referred to as 'fantasies' or 'Cinderellas'. The most dangerous types of counterfeits or fakes are covers with faked postmarks or genuine but post-war canceling devices used to enhance otherwise genuine usages in an effort to increase the value.
Cover - an envelope, post card, or folded letter sheet that has been cancelled
Cover (souvenir) - an envelope or item of postal stationery cancelled as a keepsake
Cracked plate - stamps that show evidence that the plate from which they were printed was cracked
Creased paper - a condition that creates a colorless wrinkle on a finished stamp. A crease occurs when the paper is fed into the press unevenly. A crease occurring after printing damages the stamp.
Curtiss Jenny - the Curtiss-Jenny JN-4 airplane, nicknamed the 'Jenny'. The Jenny was originally manufactured for army training use, but hundreds of surplus Jenny airplanes became available for public use at the end of the First World War. Just prior to the end of the war, six of these airplanes, designated JN-4H for their one-hundred fifty horse power Hispano-Suizo engines, were used for the first regularly scheduled Air Mail Service. Click here to learn more about the Jenny. http://www.postalmuseum.si.edu/airmail/historicplanes/postal/historicplanes_postal_jenny_long.html
Customs fee stamp - a stamp indicating payment of various customs fees excluding customs duties. Eight stamps were issued by the U.S. Postal Service between 1887 and 1918.
Cylinder numbers - numbers printed in small type on British photogravure stamps