matrix-spec/content/rooms/v9.md

title	type	weight
Room Version 9	docs	90

This room version builds on version 8 to add additional redaction rules that were unintentionally missed when incorporating v8.

Client considerations

See room version 8 for specific details regarding the addition of restricted rooms.

Clients which implement the redaction algorithm locally should refer to the redactions section below for a full overview.

Redactions

{{% rver-fragment name="v9-redactions" withVersioning="true" %}}

Server implementation components

{{% boxes/warning %}} The information contained in this section is strictly for server implementors. Applications which use the Client-Server API are generally unaffected by the intricacies contained here. The section above regarding client considerations is the resource that Client-Server API use cases should reference. {{% /boxes/warning %}}

Room version 8 added a new restricted join rule to allow members of a room to join another room without invite. Room version 9 is based upon v8 with the following considerations.

Redactions

See above.

Unchanged from v8

The following sections have not been modified since v8, but are included for completeness.

Handling redactions

{{% rver-fragment name="v3-handling-redactions" %}}

Event IDs

{{% rver-fragment name="v4-event-ids" %}}

Event format

{{% rver-fragment name="v4-event-format" %}}

Deprecated event content schemas

{{% rver-fragment name="v1-deprecated-formatting-off-spec" %}}

{{% rver-fragment name="v1-stringy-power-levels" %}}

Authorization rules

{{< rver-fragment name="v8-auth-rules" >}}

State resolution

{{% rver-fragment name="v2-state-res" %}}

Canonical JSON

{{% rver-fragment name="v6-canonical-json" %}}

Signing key validity period

{{% rver-fragment name="v5-signing-requirements" %}}