A month back, we took on the mysterious hashtag, #. Case closed. You’ve got that character down. Was it you who shared, “Tuesday our #creditunion branch served 300 members. Before lunch! #nowimhungry”?

There is another mysterious symbol hiding in plain sight. You know it as the thing in e-mails. Yes, the @. Fun fact: It has no formal name in the English language. “At sign” is the closest we have to an official reference. Spanish speakers recognize “arroba” to describe it.

It’s for more than e-mails? Yes, and it also drives all of us nuts when we have to write one on paper. It’s the (arguably) more important companion of the hashtag. Don’t tell, though. It’ll be #reallyupset.

While the hashtag identifies and unifies phrases or comments, the @ unifies people. When you put one of these little guys in front of someone’s username, it becomes a “mention”. That user then gets notified of your post. Say I shared on Twitter (tweeted): “@CUNA, great work in representing Credit Union interests nationwide!” The manager of CUNA’s Twitter account would receive a notification of my post, and they could then reply publicly by writing “@JoeCUGeek” (my Twitter handle) in their post.

All compatible services (Twitter, Facebook, Pinterest, Instagram, and many more) behave similarly. You can also make more than one mention in a post: “This #CUNAGAC is so much fun. Thank you @CUNA and @trustdotcoop for your efforts in making this possible.” Both accounts will receive a notification. Typically, public replies put the username at the beginning, while generically talking about them can be anywhere.

So you’ve got hashtags and mentions. All you need is the content! The best way to understand how these are used is to get on social media and observe, then try yourself! I always enjoy carrying a small conversation with credit unions and others over quality posts. Want to learn more? Get in touch directly @JoeCUGeek on Twitter and we’ll apply our skills together!

5/5/15 – Correction: A previous version of this post referenced and linked to an incorrect Twitter address.