On posts that you make, you can now add a little bit of additional text! Just click the flair button, then the one possible selection in the pop-up. Then type in your flair, hit save, and you're done!
This is open on all dorknet subs, except for me irl where that would spoil things.
The main intention for this is if people forget to put trigger warnings on their posts, and wish to because they forgot to put it in the title. There's no right or wrong way to do TWs, you can put it in the title before you submit, or in the flair afterwards, or both if you're feeling saucy.
You can of course use it any way you like.