Ability to assign an alias to another user in a specific room without propagating this alias

[2nd-metaman]

Hello,

it would be great if I could assign a "Nickname" or "Alias" to a person in a room, without this being visible beyond my own client.

What is the use case here?
When people join a room, they can decide how they want to be named in that room.
However, if I am e.g. trying to get some work done with people, I might not want to remember all the time what nickname they are using right now.
So if "Joe78" joins the room of my work project, I might like to locally give him the alias "Joe Miller, HR", so I dont forget who he is and that he represents the HR department.

Local renaming of users has been an option e.g. in Skype for a very long time.

[turt2live]

The room version of this is reported as https://github.com/vector-im/riot-web/issues/3130
The spec to support both cases is https://github.com/matrix-org/matrix-doc/issues/690

It would be nice if this was implemented in all of the clients though :)