Multiple group mentions based on overlapping membership

Here is what I suppose to be an easy to implement feature (correct me if I’m wrong) with great potential: multi-group mentions. More precisely: multi-group mentions based on a logical AND conjunction, @groupX∧groupY, as it were. In plain English: the message will be sent to all members who are a member of both group X AND group Y

Unless I missed something, currently you can only send notifications/messages to groups based on a logical OR conjunction, i.e. by simply mentioning multiple groups.

So what might a multi-group-and-mention be useful for? For example, imagine a multi-lingual site, where speakers of a specific language are members of dedicated language groups. Furthermore, they can also me members of groups dedicated to specific interests. Multi-group-and-mentions would make it possible to address, for example all French speaking members with a specific interest.

You can simply mention multiple groups like @groupa @groupb already.

My understanding is that @groupa @groupb will combine the two groups with an OR: the mention will go to any member who is a member in either groupa OR groupb. My suggestion is an AND conjunction: the mention will go to all members who are a member of both groupa AND groupb.

That is correct but any other behavior seems awfully strange to me.

I’m not suggesting to change any existing behaviour but to add a new one. Not sure how the AND mention should be written, but one way could be @(groupa,groupb).