IEN

1. Short for Internet Experiment Note or Internet Engineering Notes, IEN is is an early type of document that contains information relating to the Internet. For example, IEN 116 contains information about an Internet Name Server, or IEN 112 contains information about the transmission Control Protocol. Today, IEN documents are obsolete and have been replaced by other types of documents such as RFC documents. 
2. Short for Image-Enabled Netware, IEN is a version of Netware 4.x developed by Novell and Kodiak that supports special image files.

Also see: BCP, Netware, RFC, RIPE notes, RTR, STD