In order to combat the increasing amount of SEO spam posted in user's signatures--something difficult to moderate compared to just user posts and threads--the moderator team and I have decided to update the signature policy.

Registered members must have 10 or more posts in order to use a signature. If you already have less than 10 posts and already have a signature, you might need to wait until you have more posts in order to edit it. Within 24 hours (often much less) of achieving your 10th post, you will automatically be granted permission to edit your signature.

If you have 10 or more posts, are a normal registered member, but cannot edit your signature, please reply to this thread.

This restriction is unique to WDF v5. When WDF v6 gets deployed in several months, this policy will be lifted as there will be no SEO benefits of posting links at WDF at all (by design).