Social media platforms face a critical challenge in achieving interoperability through standardized content schemas. The article examines two competing protocols—ActivityPub (W3C standard powering the fediverse) and AT Protocol (Bluesky's approach)—alongside historical lessons from RSS/Atom fragmentation and Dublin Core's success. Key technical requirements include foundational metadata (unique IDs, timestamps, author attribution), content type classification, moderation flags, and extensibility mechanisms. Governance models range from open standards bodies (W3C, IETF) to consortium-based approaches (OASIS) to vendor-led standardization. The EU's Digital Services Act creates regulatory pressure for standardization, with over 735 billion moderation decisions now requiring harmonized reporting. Success would enable genuine platform choice and content portability; failure would entrench current walled gardens. The path forward requires establishing minimal core vocabularies, building on existing foundations like Activity Streams 2.0, prioritizing moderation metadata, adopting formal extension mechanisms, and balancing open governance with development efficiency.