The Accessible Platform Architectures Working Group has published a First Public Working Draft of Synchronization Accessibility User Requirements. This document outlines accessibility-related user needs and associated requirements for the synchronization of multimedia. The successful synchronization of multimedia content, especially audio and video, is essential to accessible web-based communication and cooperation. Understandable media is therefore media synchronized to very specific limits, according to multiple research studies. By clarifying the parameters of adequate synchronization, we can influence the development of future technologies, specifications, and accessibility guidelines. Comments are welcome through 5th November 2021.