Message tags

Since online classes started for a friend of mine and me, we've been sending us the notes of our teachers quite often. Now it would be quite useful if we could mark those specific messages with tags, e. g. a maths tag or a physics tag, so that we could quickly see all of those message by searching for messages by tag. That way we could easily access all of the important messages without having to search for them for long. You could make the tag visible by putting it on the right side of the user name, like a bot tag.