Just ran into this and thought others might find it useful
Wow, that would be really helpful in a lot of online disputes. It's amazing how quickly something in an online forum can spiral out of control. I'm in a humorous Facebook group called "Crap Wildlife Photography" where people post failed photos they've taken and welcome the hilarious comments about how blurry it is, or how it looks like something else, or whatever. EVERYTHING is tongue-in-cheek on there, and it can be riotously funny. Until someone doesn't get it that someone else is joking, which happens maybe once a month. This took place today.
Peter had posted a hilariously awful photo of a "Kangaroo with little Joey". And this ensued...
The first comment was obviously a joke, but the original poster took it as a serious question and answered in kind. The jokester then got rude and the OP took offense and it went horribly wrong from there. I have never seen something as awful as "it's a miracle that you dodged the coat hanger for nine months" and on something that was meant to be a humorous thread no less!
It pays to be really careful out there! Assume the best intentions of everyone. Anyone reading this thread on the forums take a mental note. Unless you're both on the same page with regard to whether "we are all joking here" or not, things can become terribly insulting easily.