In Health and Fitness, a number of members (myself included) volunteer to post any questions for people who wish to remain anonymous. I was about to post something but I didn't know how it would sound so I PMed another member and told them what I wanted to say and asked how that sounded. They gave me the feedback, I took their suggestions and made my post. I'm sure there are other members out there who would like someone to give them feedback on something they're about to post. I thought it would be cool to have a number of members volunteer so that if someone is not sure how a post sounds they can PM that particular member with it. It was helpful for me, and I wouldn't mind being that helpful to someone else. It's like you're having someone proofread your post but a lot more informal.