"End-user-defined characters (EUDC) in double-byte character sets (DBCSs) and private use area (PUA) characters in Unicode are custom characters. They can be defined and implemented either by an end user or by another party, such as an equipment manufacturer, a user group, a government body, or a font design company. Their use enables users to form names and other words using characters that are not available in standard screen and printer fonts." - scott willeke