Off-Topic

Any article that does not conform to the subject of the newsgroup. Some newsgroup users hold extremely negative opinions towards off-topic posting, while other newsgroups may be totally lenient. A number of off-topic articles may contain ""ob-"" (obligatory) content to give the article some relevance to the newsgroup.

Post

A single message on Usenet. In text newsgroups, a post is the same as an article. In binary newsgroups, due to the complexity of binary files, most posts consist of many articles.

Retention

Retention refers to the length of time that articles are available on a Usenet server before they are removed to make room for newer articles. Recently, this has become a major factor when shopping for a Usenet provider as retention times vary from provider to provider. Retention is relevant to Usenet users because longer retention gives users more opportunity to find and download an article of interest. Many Usenet providers will offer longer retention in text newsgroups because text articles require less storage space than larger binaries. Retention may also be shorter in more popular newsgroups and groups that are comprised of large binary files, such as gaming groups, due to the volume and size of posts in such groups.

Signal-to-Noise Ratio

The amount of worthwhile content compared to the amount of spam or other undesirable messages in a newsgroup. A group with a high signal-to-noise ratio has frequent on-topic posts with intelligent replies that offer more than ""me too"" comments. Groups that are frequently spammed, inhabited by trolls, or that quickly descend into flame wars usually have a low signal-to-noise ratio. This term was derived from an engineering term that also describes a useful signal versus the background interference it may experience.

single part binary file

A binary file that is small enough in size to be posted in one article. Many news servers restrict the number of characters allowed in a single article. A single part binary file is one that has fewer characters than the article limit after being encoded for posting. This limit is typically 50,000 characters but can vary depending on the news server.

Spam

Usenet Spam is generally considered to refer to a mass posting of a single message to 20 or more newsgroups, regardless of content or it may be a single unsolicited post of a commercial nature in any newsgroup, such as an advertisment for medical products, pornography, or money making schemes. Spam is also used to refer to similar phenomena in other electronic mediums. Spam is frequently used to advertise products and services of dubious repute and is successful because of its wide reach and almost inexistant cost to produce. Usenet spamming may also be used as a denial of service attack which serves to make targeted newsgroups unreadable by users. Such methods have been employed by members of entities such as the Church of Scientology to prevent criticism of their organization in alt.religion.scientology newsgroup. This method has also been utilized by commercial pornography vendors in alt.sex newsgroups to prevent the distribution of free pornographic materials to users. The term Spam is thought to have been coined from a skit by Monty Python in which a group of Viking diners at a cafe serving a menu which features SPAM in nearly every entree sing a song expressing their love for the Hormel product and repeatedly repeating the word ""SPAM"". This repetition is what was associated with flooding in chat rooms, mass emailing, and excessive Usenet posting. The widely recognized birth of Usenet Spam is dated to a January 17, 1994 post by Clarence L. Thomas IV entitled ""Global Alert for All: Jesus is Coming Soon"". Thomas, an Andrews University system administrator, claimed that a series of recent (in 1994) events were ""an indication that Jesus is coming soon"". One of the more well known Usenet Spam events, and the first commercial use of Spam, came in the form of an advertisement of legal representation for U.S. immigrants seeking enrollment in a ""Green Card Lottery"". The perpatrators were a husband and wife team of lawyers based out of Arizona who succeeded in posting their advertisment to at least 6,000 Usenet groups. With the onset of Spam in Usenet in the early 1990s came the debate over what to do about such mass repeatitive posts and advertisements in newsgroups.