Mailing lists are one of the primary forms of hacker interaction, along with Usenet. They predate Usenet, having originated with the first UUCP and ARPANET connections. They are often used for private information-sharing on topics that would be too specialized for or inappropriate to public Usenet groups. Though some of these maintain almost purely technical content (such as the Internet Engineering Task Force mailing list), others (like the `sf-lovers' list maintained for many years by Saul Jaffe) are recreational, and many are purely social. Perhaps the most infamous of the social lists was the eccentric bandykin distribution; its latter-day progeny, lectroids and tanstaafl, still include a number of the oddest and most interesting people in hackerdom.
Mailing lists are easy to create and (unlike Usenet) don't tie up a significant amount of machine resources (until they get very large, at which point they can become interesting torture tests for mail software). Thus, they are often created temporarily by working groups, the members of which can then collaborate on a project without ever needing to meet face-to-face. Much of the material in this lexicon was criticized and polished on just such a mailing list (called `jargon-friends'), which included all the co-authors of Steele-1983.