Excessive Multi-Posting (EMP) means the same as the term "spam" usually does, but is more accurate and self-explanatory. It means, essentially, too many separate copies of a substantively identical article.
"Substantively identical" means that the material in each article is sufficiently similar to construe the same message. The signature is included in the determination. These are examples of substantively identical articles:
Excessive Crossposting (ECP), also known as "Velveeta", refers to where a "lot" of postings to more than one group each have been made.
Some people think cross-posting is "bad". In and of itself, it's good behaviour - allows you to reach more groups with less impact on the net. Especially if you set the followup-to: header to one group. It is "bad" when it's done to provoke flamewars (like cross-posting how to cook a cat between alt.tasteless and rec.pet.cats), but this is not the topic of this FAQ.
This author considers the term "spam" to mean excessive postings of EMP and/or ECP variety. That is, "spam", is a generic term for several different things. The term is _supposed_ to mean EMPs only, but most people use "spam" to mean any "excessive posting".
The term "jello" means a large/combined EMP/ECP. This author doesn't believe this to be a useful term. Indeed, this author doesn't really believe any of these terms are useful - always call them "spam".
A spam, EMP, or ECP then refers to a posting that has been posted to many places. There is a consensus that there is a point at which it is abuse, and is subject to advisory cancellation.
A formula has been invented by Seth Breidbart which attempts to quantify the degree of "badness" of a spam (whether EMP or ECP) as a single number. The Breidbart Index (BI) is defined as the sum of the square roots of n (n is the number of newsgroups each copy was posted to).
Example: If two copies of a posting are made, one to 9 groups, and one to 16, the BI index is sqrt(9)+sqrt(16) = 3+4 = 7.
The BI2 (Breidbart Index, version 2) is an experimental metric, which may eventually replace the BI. It is calculated by computing the sum of the square roots of n, plus the sum of n, and dividing by two. Eg: one posting to 9, and one to 16 is
(sqrt(9) + sqrt(16) + 9 + 16) / 2
3 + 4 + 9 + 16 = 32 / 2 = 16
The BI2 is more "aggressive" than the BI, intended to cut off the "higher end". BI allows about 125 newsgroups maximum. BI2 allows a maximum of 35. At this time, no-one is using BI2 to determine when a spam is cancellable - it is included only for additional information.
The thresholds for spam cancels are based _only_ on one or more of the following measures:
These thresholds are applied to all hierarchies, not only the big8, but alt, bitnet, bionet, biz and regional hierarchies etc. Many hierarchies have more restrictive rules which are decided upon and enforced by their users and administrators.
These cancels have nothing whatsoever to do with the contents of the message. It doesn't matter if it's an advertisement, it doesn't matter if it's abusive, it doesn't matter whether it's on-topic in the groups it was posted in, it doesn't matter whether the posting is for a "good cause" or not.
Spam cancels are non-content based. They're not based on _what_ was said, they're based only on how many times it was said.
Administrators wishing to ignore spam cancels cancels can "alias out" the site "cyberspam", and the cancels will not affect your system. This is normally done at your feed site, but patches are available for INN to allow you to reject spam cancels on your own system. Ask in news.admin.net-abuse.misc if you need this patch.
Further literature on posting etiquette can be found in:
A mailing list has been set up to assist those wishing to post commercial advertisements on Usenet in a responsible fashion. Email your questions to commerce at acpub dot duke dot edu.