Several years ago I did a roll search on 2005 D Bufalo Nickels. This is what I found. A cud in the date, look closely at the top of the 2 in the date - not the best pic. I shtis worth anything more than 5c?
A cud is a damaged area resembling a blob on the surface of a coin which is raised above the field a little, and which obliterates the device or inscription where it appears. Cuds are the result of die cracks which have become severe, or from die chips where part of the die surface has become damaged and broken away. Some experts in the error-variety hobby insist that for the blob to be called a cud, the damaged part of the die must include part of the edge of the die. Although this is the purist definition, in common parlance you'll see the term "cud" used to describe the blob created by any die chip or serious die crack, regardless of its placement on the die or coin. Very small cuds are not usually valuable unless they appear on Proof coins. Cuds which can be seen by the naked eye are usually worth a small premium over normal value, and some cuds have actually been cataloged and are collectible, such as those on Morgan Dollars or between the letters of LIBERTY on Wheat Cents. I don't think your coin is of any particular value.
Call it purist if you wish but the correct definition of a cud is the raised blob on a coin - including the rim - where a portion of the die has broken away. For a portion of a die to break off it must include the rim. A die chip should not be confused with a cud. A die chip is just that - a chip. The coin posted by the OP has a die chip. From PCGS Coin Lingo
I have always been taught that cuds are at the rim. Looking in The CUD Book by Sam Thurman and Arnold Margolis (copyright 1997) on page VIII under Historical Data is the following paragraphs: " Del Ford published the term "cud" in "U.S. Major and Minor Mint Errors". In his explaination, he indicated that the error looked like a chew or cud of tobacco. This term is now commonly used by numismatic error coin collectors. Cuds are found on all denominations of U.S. and foreign coins, tokens, medals, ect. Mort Goodman spent over five years researching and collecting this variety of error. He finally settled on the following definition for the error. "An abnormally raised area of metal, on the field or design of a numismatic product, involving the edge of the die and caused by a broken die." This section then goes on to say Mort Goodman published "The Design Cud" in 1969 which was a catalogue with over 424 illustrations of cuds (with all at the edge of the coin). So this term has been around a long time and has always meant the edge. Maybe it is common to see the term used for die chips in the middle of the coin somwhere but that doesn't mean the term is being used correctly. I think the common place to see this is ebay, and ebay is the worst place to assume terms are used correctly.
