Adding custom fields to email template records?

I noticed there is no Email or Email Tempates listed in Studio.  We'd like to add a field or two to classify our different email templates, say we send different emails to prospects based on the business industry they are in so we'd like to add an 'industry type' field to the template.  Looks like this isn't possible (at least not through the interface.) So at this point we are putting the industry in parentheses in the template name which is kind of a clunky way to doing it.