Banning / Restricting / Redacting / Muting / Filtering / Blocking Out List of Words

Description:

Hello! I'm not sure if this is the right avenue to submit this request, so please let me know if it should be moved.

Use Case: What I would like to do?

As a room owner and/or moderator, I would like the ability to maintain a private list of keywords, terms, phrases that aren't allowed in a room.
As a user, I would like the ability to mute or filter out certain keywords from all messages

Why add this feature?

Alleviate moderation work
Provide healthier environments for community members, based on the established rules and the purpose of the room
Conform to an organization's code of conduct
Stop abusive content at the source, before it reaches the community

Examples from other services:

Discord Automod: https://support.discord.com/hc/en-us/articles/4421269296535-AutoMod-FAQ

Telegram (public bot): https://botostore.com/c/grep_robot/

Mastodon: https://docs.joinmastodon.org/user/moderating/#filters

Peertube (glavliiit plugin): https://joinpeertube.org/plugins-selection

YouTube: https://support.google.com/youtube/answer/9483359?hl=en#zippy=%2Cblocked-words

How it could work

Moderator/owner side: Paste, upload a txt file, or type a list of words that could result in a user getting...

A warning
Comment held under review for moderation
Kicked
Banned

User side (wishing to mute terms): Much like ignoring a user, messages containing muted terms will not be seen by the user.

User side (sending banned word in a room): "Warning" word: An alert is sent warning the user that they're using terms that are restricted in the room so that they have the chance to rewrite their message

"Hold - moderation" word: User is warned that their message has to be reviewed for moderation

"Kicked/Banned" word: User is automatically kicked or banned once they attempt to send the message.

matrix-org / synapse