3786-acl-notifs.md

MSC3786: Add a default push rule to ignore m.room.server_acl events

m.room.server_acl events allow for expressing which servers can participate in a room. Room server ACLs aren't something the user should have to worry about, so these events should not trigger notifications; however right now they do trigger notifications, if the user has the room rule set to notify (All messages in Element).

Additionally, these events are often sent quite frequently during spam attacks, which causes the users to be overwhelmed by notifications. (See element-hq/element-web#20788.)

Due to these problems, this MSC proposes a new push rule to ignore these events. The new push rule is analogous to .m.rule.member_event (see https://spec.matrix.org/v1.2/client-server-api/#default-override-rules), or .m.rule.reaction (from MSC2153 or MSC2677).

Proposal

A new default override rule is to be added that ignores m.room.server_acl events:

{
    "rule_id": ".m.rule.room.server_acl",
    "default": true,
    "enabled": true,
    "conditions": [
        {
            "kind": "event_match",
            "key": "type",
            "pattern": "m.room.server_acl"
        },
        {
            "kind": "event_match",
            "key": "state_key",
            "pattern": ""
        }
    ],
    "actions": []
}

This new push rule is inserted immediately after .m.rule.tombstone.

Unstable prefix

During development, .org.matrix.msc3786.rule.room.server_acl is to be used instead of .m.rule.room.server_acl.