on Slashdot. Users with high "karma" are eligible to become moderators themselves. The system does not promote regular users as "moderators" and instead assigns five moderation points at a time to users based on the number of comments they have entered in the system – once a user's moderation points are used up, they can no longer moderate articles (though they can be assigned more moderation points at a later date). Paid staff editors have an unlimited number of moderation points. A given comment can have any integer score from −1 to +5, and registered users of Slashdot can set a personal threshold so that no comments with a lesser score are displayed. For instance, a user reading Slashdot at level +5 will only see the highest rated comments, while a user reading at level −1 will see a more "unfiltered, anarchic version". A meta-moderation system was implemented on September 7, 1999, to moderate the moderators and help contain abuses in the moderation system. Meta-moderators are presented with a set of moderations that they may rate as either fair or unfair. For each moderation, the meta-moderator sees the original comment and the reason assigned by the moderator (e.g. troll, funny), and the meta-moderator can click to see the context of comments surrounding the one that was moderated. Features Tags Slashdot uses a system of "tags" where users can categorize a story to group them together and sorting them. Tags are written in all lowercase, with no spaces, and limited to 64 characters. For example, articles could be tagged as being about "security" or "mozilla". Some articles are tagged with longer tags, such as "whatcouldpossiblygowrong" (expressing the perception of catastrophic risk), "suddenoutbreakofcommonsense" (used when the community feels that the subject has finally figured out something obvious), "correlationnotcausation" (used when scientific articles lack direct evidence; see correlation does not imply causation), or "getyourasstomars" (commonly seen in articles about Mars or space exploration). Culture As an online community with primarily user-generated content, many in-jokes and internet memes have developed over the course of the site's history. A popular meme (based on an unscientific Slashdot user poll) is, "In Soviet Russia, noun verb you!" This type of joke has its roots in the 1960s or earlier, and is known as a "Russian reversal". Other popular memes usually pertain to computing or technology, such as "Imagine a Beowulf cluster of these", "But does it run