An exclamation point could mean that your domain is not listed for sale, or the domain has not yet been verified for ownership. It could also mean traffic to the domain has not yet been tracked if the domain has been parked. Once you receive at least one unique view to all of your domains, you should no longer see the exclamation point, and the domains will then also appear in the "Statistics" area of "Domain Parking."
You can still edit settings related to selling and parking these domains.