Social media platforms have been establishing content moderation guidelines and employing various moderation policies to counter hate speech and misinformation. The goal of this paper is to study these community guidelines and moderation practices, as well as the relevant research publications, to identify the research gaps, differences in moderation techniques, and challenges that should be tackled by the social media platforms and the research community. To this end, we study and analyze fourteen most popular social media content moderation guidelines and practices, and consolidate them. We then introduce three taxonomies drawn from this analysis as well as covering over two hundred interdisciplinary research papers about moderation strategies. We identify the differences between the content moderation employed in mainstream and fringe social media platforms. Finally, we have in-depth applied discussions on both research and practical challenges and solutions.

翻译：社交媒体平台一直致力于制定内容审核准则，并采取多种审核政策来应对仇恨言论和虚假信息。本文旨在研究这些社区准则和审核实践，以及相关研究文献，以识别研究空白、审核技术差异，以及社交媒体平台和研究界应共同应对的挑战。为此，我们研究并分析了十四个最流行的社交媒体内容审核准则与实践，并对其进行整合。随后，我们基于此分析提出了三个分类体系，并涵盖了200多篇关于审核策略的跨学科研究论文。我们识别了主流社交媒体平台与边缘社交媒体平台在内容审核实践上的差异。最后，我们针对研究与实践中的挑战和解决方案进行了深入的应用讨论。