How to avoid mentioning (or recognize) users with no viewing permissions?

[Andrea Boerio]

Hi, 

given that the case of trying to mention users that have no view permission on a page should be probably not frequent, indeed it happens sometimes.

If I'm the person who's mentioning somebody on a page, or on a comment on the same page, how can I realize that this person won't receive any notification?

I might be waiting for some kind of feedback from him, just to discover then that he's not even aware of having been mentioned.

Is there any way to handle this "exception" :-)? An event to fire some kind of warning?

eg. "You've been mentioned  by ... on a page that you can't have access to"

or "You've mentioned ... but he/she won't be able to see the page and won't receive any notification"

Thanks, ciao, Andrea