How do you refer to a member here?

[FlyingClayDisk]

This might provide some answers at a later date https://community.mybb.com/thread-227384.html

If I had to guess we currently use this plugin https://community.mybb.com/mods.php?action=view&pid=29

Also an alternate plugin here https://community.mybb.com/mods.php?action=view&pid=558

and here https://community.mybb.com/mods.php?action=view&pid=885

Hope that helps!

Well, thanks...but we already tried the "@" symbol and that didn't really work the way we had hoped.  I'll look through the other links you provided, but I thought I'd just communicate that much.  Thanks again!

edit - I looked through the rest of the links you provided, and you can see from my link in the reply to Encia22 above, I tried virtually every bbcode trick and prefix I know of, and the only one which did anything at all was the "@" symbol, but this doesn't send an alert to the member being tagged, it only provides an (invisible) hyperlink to their profile.  I guess you could PM/DM that member with a quick "I tagged you in a post" message, but that's way too difficult so I doubt anyone would do this.  Regarding the 3rd link you provided, I'd have to understand more about which versions (if any) of PHP (or other) software is being used to explore any of that further, but the net result is the same; there doesn't appear to be any special character or sequence which automatically triggers a notification alert when you tag someone.

The search continues.

(but thanks again).