It is a forum where debates are held on whether a grey zone character (such as Severus Snape, Mrs. Puff, and Jorgen Von Strangle) is a hero or villain, and also contains a space where people can talk about grey zone itself (such as thoughts on types of grey zone characters, tips on writing grey zones, what makes characters grey zoned in the first place, etc.).

The link is Home | Grey-zone (proboards.com)