One of the motivations for creating the World Coin Database was that I was not satisfied with how other sites cataloged world coins. Most rely on the Standard Catalog of World Coins published by Krause Publications, which is a great resource, but the website is not very user-friendly. The World Coin Database aims to create a very versatile and thorough cataloging system, utilizing links to Wikipedia articles for extensive information, as well as references to specific coins on other cataloging websites. This page attemps to describe the rationale behind how coins are organized in the World Coin Database, and can be used as a reference for cataloging your collection. The topics below represent different levels of cataloging, from less specific to more specific.
It should be noted that the World Coin Database only includes modern, milled (machine-struck) coinage that is or has been used as currency (such as business strikes and NCLT). Therefore, ancient coins, hammered coins and exonumia (tokens, medals, etc.) are excluded.
Regions are actually the top level of organization in the World Coin Database, are are merely a navigational aid.
The countries (or more generically "issuers") listed in the World Coin Database have four different names: Common, Formal, Krause, and Wikipedia. The Common name is just that: a short name commonly used to refer to the country. We rarely say "People's Democratic Republic of Algeria" instead of just "Algeria". The Common name can refer to multiple distinct "versions" of the country, which typically represent changes in government, and usually changes in coinage, flag, etc.. If there is more than one version of a country, superscripts are used to differentiate between the versions. The smaller the superscripted number, the older the version of the country. These superscripts may change as countries are added to the database. The Formal name is the "official" name for the version of the country, usually reflecting the type of government. The Krause name is the country name used by the Standard Catalog of World Coins, and is usually the same as the Common name. The Wikipedia name is the name of the Wikipedia article that refers to that version of the country. A single Wikipedia article may contain references to many different versions of countries. The dates in which the version of the country existed are also listed to help users to determine which to select when cataloging coins.
Some coins are minted for multiple countries, but usually contain the name of one organization, as in the case of the East Caribbean States and West African States. In these cases, the Common name for the "country" of the coin is the name of the organization as it is spelled on the coin (in English). Other coins are minted specific to certain subdivisions within countries, such as the States of Germany and Provinces of China. This can be another level of cataloging, but the World Coin Database simply notates this accordingly and does not create separate subdivisions (at the moment).
Every coin in the World Coin Database is required to be linked to a currency, along with its relative value with respect to that currency (0.25 USD e.g.). The relative values are used to sort search results and can be viewed in every coin's detail page. The currency list includes the name (and Wikipedia link), ISO 4217 code (if available), date range used, and if the currency has been replaced, what currency replaced it and at what rate (old units per 1 new unit).
Currencies are replaced by issuers a few different ways. One way is an outright replacement with a new currency, such as the Euro replacing member country currencies. Another way is called a revaluation. Revaluation can involve the currency being "officially" replaced, and given a new ISO 4217 code while maintaining the same name. Revaluation can also be done "unofficially", where the "old" coins and paper money become obsolete and new ones are issued, essentially only affecting the exchange rate between itself and other currencies. This type of revaluation is rare, but has occurred in Nicaragua and North Korea.
The denomination is the amount of currency the coin is designated at the time of issue, consisting of a number and a unit. The unit can be equal to the currency, a subunit of the currency, or even a superunit of the currency. The denomination listed in the World Coin Database is what is printed on the coin itself, with the number converted to numerals and the unit translated into Basic Latin characters, if necessary. For example, the denomination on the current United States 10 cent coin is not "10 cents", but actually "one dime". However, most coins have denominations in units of its currency ("dollar" e.g.) or 1/100 of its currency ("cents" e.g.). The World Coin Database defines the value of a coin with respect to its original currency ("one dime" = 0.1 USD), and does not provide pricing information.
A coin type refers to a country's denomination with a unique shape, size, design, pattern, and/or composition. A single type may be produced with many dates, mint/privy marks, or varieties. The type is the lowest level of cataloging in the World Coin Database, as well as the Standard Catalog of World Coins. The Standard Catalog of World Coins assigns each type a Krause-Mishler (KM#) or Yeoman (Y#) number/code (unique by country). Type collections (one of each type) are very popular for collecting world coins, while "date" collections (one of each date, and possibly mint/privy mark) are usually specific to one country.
Most coins use the Gregorian calendar, which uses the Anno Domini (AD) era. However, some countries use other date systems, which can make cataloging difficult. Check out my date systems and conversion guide here. Currently, the World Coin Database uses 9 date systems. The World Coin Database allows searching in any date system, and performs the conversion automagically. See the table below for a description of the date systems.
|Name||Code||Used By||Wikipedia Artcile|
|AD||Most countries||Gregorian calendar|
|BC||Most countries||Gregorian calendar|
|Buddhist (Era)||BE||Thailand||Buddhist calendar|
|Chula Sakarat||CS||Thailand||Chula Sakarat|
(M. R. S. P.)
|MS||Iran||Mohammed Reza Pahlavi|
|French Republican (Era)||RE||France||French Republican Calendar|
|Rattanakosin Sok||RS||Thailand||Thai solar calendar|
|Sexagenary Cycle||SC||China||Sexagenary cycle|
|Solar Hijri||SH||Iran||Solar Hijri calendar|
Mint marks are small symbols or letters, that specify where the coin was minted (such as the city where the mint is located). Privy marks are similar, and sometimes identify the engraver, but also exist simply to make the coin different for marketing puposes. Mint and privy marks should not be confused with marks made by the desinger (such as their initials), as they are considered to be part of the design of the coin, similar to how a painter's signature becomes part of the painting. The same coin design can have many different mint and privy marks applied, similar to how dates are changed. See my guide on mint and privy marks for various countries here.
Varieties can come about in two ways. The first come from striking errors or variations in the die patterns at the mint. These types of varieties are usually rare and can be very valuable. The second come from post-production alterations (by the mint or third parties), which can include additional privy marks or colorations. These are usually removed from or never included in circulation, and sold only to collectors.
The condition of the coin is directly proportional to its value as a collectible. The better the condition, the more valuable. The conditions of coins are typically assigned a rating or grade, which criteria can vary for each coin. These ratings are based on even wear, so if a coin has isolated blemishes such as scratches, corrosion, or discoloration, it is less attractive, and therefore the grade will be somewhat lower. Also, coins that appear to have been cleaned are typically less valuable, as the process sometimes creates unnatural appearances. Therefore, only gently remove loose dirt and never scrub a coin. Below is a table of of the Sheldon grading system commonly used for United States coins.
|PO-1||Poor: Identifiable date and type|
|FR-2||Fair: Mostly worn, though some detail is visible|
|AG-3||About Good: Worn rims but most lettering is readable though worn|
|G-4||Good: Slightly worn rims, flat detail, peripheral lettering nearly full|
|G-6||Good: Slightly worn rims, flat detail, peripheral lettering full|
|VG-8||Very Good: Design worn with slight detail|
|VG-10||Very Good: Design worn with slight detail, slightly clearer|
|F-12||Fine: Some deeply recessed areas with detail, all lettering sharp|
|F-15||Fine: Slightly more detail in the recessed areas, all lettering sharp|
|VF-20||Very Fine: Some definition of detail, all lettering full and sharp|
|VF-25||Very Fine: Slightly more definition in the detail and lettering|
|VF-30||Almost complete detail with flat areas|
|VF-35||Detail is complete but worn with high points flat|
|EF-40||Extremely Fine: Detail is complete with most high points slightly flat|
|EF-45||Extremely Fine: Detail is complete with some high points flat|
|EF-45+||Extremely Fine: Detail is complete with a few high points flat; superior eye appeal|
|AU-50||About Uncirculated: Full detail with friction over most of the surface, slight flatness on high points|
|AU-50+||About Uncirculated: Full detail with friction over most of the surface, very slight flatness on high points; good eye appeal|
|AU-53||About Uncirculated: Full detail with friction over 1/2 or more of the surface, very slight flatness on high points|
|AU-53+||About Uncirculated: Full detail with friction on only 1/2 of surface, very slight flatness on high points; good eye appeal|
|AU-55||About Uncirculated: Full detail with friction on less than 1/2 of surface, mainly on high points|
|AU-55+||About Uncirculated: Full detail with slight friction on less than 1/2 of surface, on high points; good eye appeal|
|AU-58||About Uncirculated: Full detail with only slight friction on the high points|
|AU-58+||About Uncirculated: Full detail with the barest trace of friction on the highest points; superior eye appeal|
|MS-60||Mint State: No wear; may have many heavy marks/hairlines, strike may not be full|
|MS-61||Mint State: No wear; multiple heavy marks/hairlines, strike may not be full|
|MS-62||Mint State: No wear; slightly less marks/hairlines, strike may not be full|
|MS-62+||Mint State: No wear, still slightly less number of marks/hairlines, strike may not be full|
|MS-63||Mint State: Moderate number/size of marks/hairlines, strike may not be full|
|MS-63+||Mint State: Average number of marks/hairlines, strike will be close to average; good eye appeal|
|MS-64||Mint State: Few marks/hairlines or a couple severe ones, strike should be average or above|
|MS-64+||Mint State: Very few mint/hairlines or a couple of heavier ones, strike should be average or above; superior eye appeal|
|MS-65||Mint State: Minor marks/hairlines though none in focal areas, above average strike|
|MS-65+||Mint State: Very minor marks/hairlines though none in focal areas, above average strike and eye appeal|
|MS-66||Mint State: Few minor marks/hairlines not in focal areas, good strike|
|MS-66+||Mint State: Very few minor marks/hairlines not in focal areas, very good strike with superior eye appeal|
|MS-67||Mint State: Virtually as struck with minor imperfections, very well struck|
|MS-67+||Mint State: Virtually as struck with very minor imperfections, very well struck with attractive eye appeal|
|MS-68||Mint State: Virtually as struck with slight imperfections, slightest weakness of strike allowed|
|MS-68+||Mint State: Virtually as struck with very slight imperfections, the strike must be virtually full; eye appeal must be very good|
|MS-69||Mint State: Virtually as struck with miniscule imperfections, near full strike necessary|
|MS-70||Mint State: As struck, with full strike|