This room version builds on version 9 to enforce that power level values be integers, and to introduce a new knock_restricted join rule, allowing prospective members to more easily join such a room. Client considerations This room version adds a new knock_restricted join rule to allow prospective members of a room join either through knocking (introduced in room version 7) or through “join restrictions” (introduced in room version 8 and refined in room version 9).| Matrix Specification
Rooms are central to how Matrix operates, and have strict rules for what is allowed to be contained within them. Rooms can also have various algorithms that handle different tasks, such as what to do when two or more events collide in the underlying DAG. To allow rooms to be improved upon through new algorithms or rules, “room versions” are employed to manage a set of expectations for each room. New room versions are assigned as needed.| Matrix Specification