Ironic that I read this question a year after posting. This is already possible in Global Change for Events. In the "Event Attributes" section, right at the top, simply find the "Attributes" field - it's the one without the + next to it. It should be at the top of the list, but it's there, alphabetically sorted. Just select that field, and you can add an attribute, a description, a date, and a comment, that will be added to all events, or just the selected events. Hope this helps you, Richard. If not, perhaps I misunderstood your request.