A nickname is
|“||[a] combination of two separate unclassified words that is assigned an unclassified meaning and is employed only for unclassified administrative, morale, or public information purposes.||”|
A common practice is for a user to create nicknames that suggests their interests or hobbies. Nicknames may be preceded by a special character denoting additional privileges for that user. For example, a channel operator on an IRC network is identified by the “@” symbol in front of his nickname.
A nickname generally is not permanently reserved for a specific individual and therefore cannot be relied on to identify a person. Each user in a chat room, IM system or IRC network must have a unique nickname while logged on. In most cases, when that individual logs off, that nickname is available for use by another individual. Just because the same nickname is seen on another occasion does not necessarily mean the same user was using the nickname.
- Office of Counterintelligence (DXC), Defense CI & HUMINT Center, Defense Intelligence Agency, "Terms and Definitions of Interest for DoD Counterintelligence Professional," at GL-129 (May 2, 2011) (full-text).