This document outlines antipatterns that can harm open source communities. It discusses issues related to governance, communication, culture/environment, merit, decision making, leadership, balancing forces, and other concerns. Specific antipatterns mentioned include having too much or too little governance, keeping community operations private, being restrictive about approved communication channels, failing to actively pass on culture to newcomers, prioritizing rules over guidelines, making criteria for success vague, creating an unfriendly environment, believing merit can be absolutely measured, ignoring leadership needs, being partisan, making community building someone's job rather than developers, and centralizing by giving people turf. The document aims to help open source communities avoid these pitfalls.