NOTE TO ANYONE LOOKING IN ON THIS: I've modified the Article DW and removed the "required" on the message field so that you will be able to set the MIN Characters to 0 which will make the Article Message field OPTIONAL.Not without customization as the Article DataWriter requires that field. I MIGHT adjust that in the future, but for now, even if you set the MIN Characters to 0, the DataWriter is going to throw an error if it doesn't contain at least 1 character as its a required field).
You'd be better off WAITING for the next release of AMS vs trying to figure out how to do that on your own (which would require programming). The next version of AMS removes the "required" setting for that field which allows you to set the MIN Characters to 0 which in turn makes that field optional (you can even edit the Create and Edit Forms and wrap the input with a conditional based on Category IDs so that it doesn't display for specific categories. BROGAN has a complete guide on conditionals that has THE information you'd need to do that kind of customization (and there are 1000's of members that could help you with it).Or can I make the field smaller and change the name of the field from article to notes just for that category?