As part of the Ethics of Content Labeling Project, we present a comprehensive overview of social media platform labeling strategies for moderating user-generated content. We examine how visual, textual, and user-interface elements have evolved as technology companies have attempted to inform users on misinformation, harmful content, and more. We study policy implementation across eight major social media platforms: Facebook, Instagram, Twitter, YouTube, Reddit, TikTok, WhatsApp, and Snapchat. This archive allows for comparison of different content labeling methods and strategies, starting when platforms first implemented labeling tactics, through the early months of 2021. We evaluate policy response to real-world events and the degree of friction labels have against user interaction with harmful content.