Read the fine print for submissions and pay attention to it all because they are sticklers. I mean, most editors and their readers tend to be a little cranky because their slush pile is full of people who outright ignore submission guidelines, which is understandable. But Clarkesworld has like a no-tolerance policy. So, just be aware of that when you submit something to them.

On the other side of that, they are a good, quality, highly respected online zine, and one of the zines that counts towards professional publication if you want to join the SFWA. Getting published in Clarkesworld would be really good, no matter what.