2.3 KiB
MSC4210: Remove legacy mentions
Matrix v1.7 introduced intentional mentions, where events list users they
mention explicitly, instead of the recipients inferring mentions from the raw
message text. For backwards-compatibility reasons, messages without the new
m.mentions field still use the old plaintext matching for mentions.
Plaintext matching means it's very difficult for automated tools to tell which users are mentioned in a message. This means that it's easy to spam mentions by simply not using intentional mentions.
If intentional mentions are mandatory, automated tools could easily ban users who send more than X mentions in a single message. There could even be a new push rule condition to allow checking the number of mentioned users and skip notifying entirely.
Proposal
Support for legacy mentions is dropped. Specifically, the following deprecated standard push rules are removed entirely:
.m.rule.contains_display_name.m.rule.contains_user_name.m.rule.roomnotif
Additionally, the contains_display_name push rule condition is deprecated.
Including an empty m.mentions key is still required for clients that are
aware of intentional mentions, as omitting it would cause current clients to
assume messages are not using intentional mentions.
Potential issues
Users using old clients (which don't send intentional mentions) will no longer be able to mention users on up-to-date clients/servers.
Users using old clients (which don't support the new push rule conditions) will also no longer be notified for mentions in case the client depends on the push rules served by the server.
Alternatives
The removal could be done in a new room version, such as when switching to extensible events, as suggested by MSC3952. However, such a migration will likely take much longer than clients implementing intentional mentions. Additionally, the room upgrade UX is still an open issue, which means many rooms simply don't upgrade. Therefore, making a slightly breaking change to existing room versions seems like the better option.
Security considerations
This proposal doesn't add any features, so there are no new security considerations.
Unstable prefix
Not applicable, this proposal only removes features.
Dependencies
None.