Usenet articles are propogated throughout the entire Usenet network using a method known as store and forward. This is a technique in which a posted article is stored on one computer, which then send a copy of that article to another computer. In turn, that computer sends another copy of the article to another computer, and so on. This process continues until every news server has a copy of the article. While this might seem rather inefficient, this process actually works quite well by eliminating the need for a central Usenet server, which would be under a tremendous amount of stress.

Message ID's

Usenet articles are each identified by a unique message ID. The message ID's are usually assigned to posted articles by the poster's news server. They have the format of: <Unique string>@<Full domain name>, where the unique string is a series of assigned letters and numbers unique to that article and the full domain name is simply the full domain name (news.domain.tld) of the poster's news server. It is suggested that a single message ID be used by a news server no more than once every two years to ensure that no two articles have the same message ID's at the same time.

Message ID's are used by news servers and newsreaders to locate and transfer Usenet articles. In addition, articles can be manipulated by news administrators using their message ID's (with the use of a control message).

Control Messages

News administrators can manipulate Usenet articles and newsgroups by means of control messages. Control messages are special articles posted to the control newsgroup containing commands that instruct news servers to perform specified tasks. A control message follows the following format:

Path: [path]
From: userx@news.domain.tld
Newsgroups: control
Subject: cmsg <control command> <newsgroup|message ID>
Control: <control command> <newsgroup|message ID>
Approved: userx@news.domain.tld
Message-ID: <306982.693028@news.domain.tld>
Date: [date]
Lines: 1

A brief explanation of the control message is sometimes included.

There are many control commands that can be used, each with their own parameters and syntax. Following are brief descriptions of some of the most frequently used control commands.

Cancel Message

The cancel command, used in conjuntion with a message ID, is used to delete a Usenet article from all news servers. The Subject: and Control: fields should appear as follows:

Subject: cmsg cancel <message ID>
Control: cancel <message ID>

A brief explanation as to why the message is being canceled is sometimes included in the body of the message.

Newgroup Command

The newgroup command is used to create a newsgroup and/or newsgroup hierarchy. Some news servers automatically accept all newgroup request, while some must be approved by the local news administrator. The Subject: and Control: fields should appear as follows:

Subject: cmsg newgroup <newsgroup name>
Control: newgroup <newsgroup name>

In the body of the message, a brief description of the group's purpose should be included. For example:

For your newsgroups file:
tlh.example.group            A group for the discussion of example groups.

The rmgroup command is used to remove an existing newsgroup from all news servers. Some news servers automatically accept all rmgroup requests, while some must be approved by the local news administrator. The Subject: and Control: fields should appear as follows:

Subject: cmsg rmgroup <newsgroup name>
Control: rmgroup <newsgroup name>

In the body of the message, a brief description of why the group is being removed, and who (or what organization) has approved of its removal should be included.