The most established and popular hierarchies on the USENET system belonged to the Big 8 hierarchies, those created in the mid-1980s to help deal with the increasing popularity of the USENET system. There are five other hierarchies, however, called the Five Alternative hierarchies or, simply, the alternative hierarchies.
These hierarchies are subject to the same approval process where the creation of new groups is concerned as are the mainstream hierarchies and contain many high-quality groups. The alternative hierarchies are not all the same as the alt hierarchy, which has absolutely no standards for the creation of groups whatsoever.
The five alternative USENET hierarchies do have excellent groups to offer. When people talk about the 9,000 or 10,000 groups on USENET that represent the best examples of what a USENET group should be, they usually include some groups from these hierarchies among them. The alternative hierarchies include:
All of these various hierarchies are useful, accepting the alt hierarchy. This hierarchy is notorious for bogus groups and for having a lot of spam. The process for creating a group in the alt hierarchy is looser than it is for all of the other hierarchies.
The five alternative USENET hierarchies, however, do offer some interesting materials. Bionet is an excellent hierarchy for scientific information and the bit hierarchy contains materials that were taken from the Bitnet mailing list.
Many of these newsgroups, however, have been spammed to the point where people don’t use them very often anymore and were many servers don’t even bother to carry them. Particularly where the alt hierarchy is concerned, servers oftentimes opt to just leave many of the newsgroups under that hierarchy off of their servers altogether.
There is a host of different hierarchies on the USENET, many of them regional or otherwise specific to certain corporations or certain interests to the point that they’re not carried by every server.
The Five Alternative hierarchies, along with the Big 8 hierarchies, constitute the most regulated newsgroups on the USENET system. When a group is created within these hierarchies, it goes through a very difficult approval process and there is generally enough demand to merit the creation of the newsgroup.
Because of this, you can be certain that most of the newsgroups within these hierarchies will have enough people to make them interesting places to visit and enough discussions to make interesting repositories of information. Outside of these hierarchies, there are no restrictions on how newsgroups are created and there are generally few newsgroups that are of the high quality that is associated with these two principal groups of hierarchies.