Atheist - I am not a fan of acronyms - I worked for forty-three years for a bureaucracy so I have had my fill for a lifetime - but they are a fact of life, especially on the internet.
Another fact of life on the internet is learning that how anyone presents themselves is only ever going to be a snapshot of the individual - and those snapshots are inevitably open to misinterpretation.
If you spend a lot of time on sites like this - and I do - then accepting that people will get the wrong idea about you, and not be remotely shy about letting you know (!) is simply a fact of life, and most people learn to live with it.
Personally, I roll with most misconceptions about me - I will challenge anything patently untrue, and I will respond to personal attacks, but aside from that, I try not to let such things bother me too much.