A normal forum poster that takes it upon themselves to push forum rules and tell everybody how to conduct themselves instead of leaving it up to the mods. Typically reserved for people that don't know what they're talking about, act like they have some kind of authority, and/or are obviously doing what they're doing to try to score points with the real mods and become moderators themselves. (especially if it becomes a regular thing for them and/or they don't contribute much good to the community otherwise)
A typical minimod would go into a thread where several members are in an intense, hostile argument that hasn't degenerated to the point where nobody's having an intellectual discussion anymore and tell everybody to stop flaming and trolling each other, and possibly that they'll be banned if they continue.
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