Cachet - A hand stamp or printing placed on a letter or postcard by an institution other than a Post Office. They were usually designed and used to commemorate a special event or circumstances under which the item was mailed. Sometimes an official government hand-stamped cancel that contains an unusual design is also referred to as a cachet.

Cancel - Cancellation - The placement of a mark over postage to designate that it has been accepted into use by a postal system, and to prevent it from being used for postal services again (it can also be a pen mark). Cancel often includes a date, rate, route, or place of mailing. Similar term to Postmark.

Cancelled to order - (also called CTO) - A stamp that the postal service has canceled (marked as used) before selling it to a stamp collector or dealer. Postal services of various countries do this in response to collector demand, or to preclude stamps issued for the collector market being used on mail.

Cash on Delivery (COD) - Service, which collects the cost of postage and the product enclosed from the recipient and forwards it to the mailer.

CDS - Abbreviation of 'circular date stamp' used for cancelling the stamp by the postal authorities.

Censored Mail - A postal item bearing a handstamp or label indicating that the item has been opened and read by a censor.

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 or JNF labels are examples.

Charge Marks - On early letters, generally pre-philatelic letters or figures (either manuscript or stamped) that were used to indicate fees for letters to be settled by the recipient, or that have been settled by the sender (see Accountancy Mark).

Cliché - The individual unit consisting of the design of a single stamp, combined with others to make up the complete printing plate. Individual designs on modern one-piece printing plates are referred to as subjects.

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 have a straight edge on two parallel sides and perforations on the remaining two parallel sides.

Color trial - Postage stamp printed singly or in multiple, in a particular shade of ink, to judge aesthetic appearance, prior to final decision on the issued color.

Col Vapore - (Italian) By steamer, abbreviation CV.

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.

Compulsory Registration - Occurs when an item, not sent registered, is suspected to contain something of value, coins, banknotes, postage, jewelry etc.; the item is then registered by the post office and the registration fee (single or double) is charged to the recipient.

Control - Letters and/or figures printed in a postage stamp sheet margin to indicate time of accounting, distribution or other manufacturing data. Examples are sheet serial numbers on the backs of stamps, dates in sheet margins, and overprints added to prevent the use of stolen stocks.

Counterfeit - An item, usually a replica of an existing stamp, made to defraud collectors. The term can also be applied to overprints, postmarks, etc. 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. They are also often referred to as 'fantasies' or 'Cinderellas'. The most dangerous types of counterfeits or fakes are covers with faked postmarks used to enhance otherwise genuine usages in an effort to increase the value.

Cover - A paper sheet that is meant to wrap mailed correspondence for protection and privacy. Eventually, covers were manufactured in the form we now refer to as an envelope. They did not become common until regulations that required them to be counted toward postage, charged by the page, were repealed.

Crash cover - A philatelic term for a type of cover, (including the terms air accident cover, interrupted flight cover, wreck cover) meaning an envelope or package that has been recovered from an aircraft, airship or airplane crash, train wreck, shipwreck or other accident. Crash covers are a type of interrupted mail.

Collins - "The Ottoman Posts & Telegraph Offices in Palestine & Sinai" - Norman J. Collins & Anton Steichele - Published 2000 by Sahara Publication Ltd