I'm happy to announce that we've introduced a new feature, that will allow members to tag each other in posts.
IMPORTANT: Please read the rules at the end of this post to avoid misusing this plugin to break forum rules, risking a permanent account ban!
Several new tabs have been added to your profile page:

Here are the 3 ways to use this plugin:
1)Mention Someone in a Post
To mention someone in a post, simply type "@" along with their STM username, such as "@vortex".

They'll see a notification in their profile:

2)Notify Someone When Quoting Their Content
Also, if you quote a part of someone's post:

They'll receive a notification.

3)Tag Someone in a Thread
You can also tag users above a thread, to alert them to the thread:

When you do, they'll get notified:

Rules For Using the Tagging Plugin
1)Attention to Vendors especially: Please DO NOT use this plugin for promotion purposes!
Unless a user has EXPLICITLY asked for recommendations for the type of service you're offering, please do not mention/tag users to draw attention to your business.
Doing so will result in a warning. Breaking forum rules twice will result in a permanent account ban.
Sorry for sounding harsh - we very much value our members' experience here. Most vendors are valuable contributors and are much appreciated, but it only takes a few aggressive promoters to ruin things for everyone.
Thank you very much for your cooperation!
2)For all members: If you have a follow-along thread, and would like to request help from a moderator, you can tag up to ONE mod/member to alert them to your thread (using the "Tag user(s)" box at the top). That is not a guarantee that the person you tag will actually have time to help out, but if they don't, another mod or veteran member will likely jump in to help answer questions. (I've set a hard limit of 1 tag per thread, so choose wisely!)
3)For all members: When responding to something that someone else has said, please feel free to mention them in a post! (I've set a hard limit of 2 mentions per post - should be enough. This is to guard against abuse.)
Basically, DON'T SPAM and USE RESPONSIBLY. Before tagging someone, ask yourself "would they likely appreciate the tag, or no?" and act accordingly.
Lastly: We reserve the rights to revise the rules at any time.
And if things get out of hand and members start to abuse this plugin, we will remove this feature. But let's hope that since most of us are responsible adults, that we can all use this plugin to improve communications within the forum, instead of abusing it to ruin the fun for everyone.
Have fun tagging! 
Amy
Nice one, let's see if the members find it useful
Could be a great tool for those who start follow alongs or need urgent help from the mods.
Yeah sometimes I forget I've posted something in a thread. If the relevant person can tag me and I get a "mention" surely will pick it up!
Very nice addition, slack-style!
Will be useful to get my attention on threads I might have missed normally.