When we add a new feature to our web application, I insert a "NEW FEATURE" banner into the appropriate page. e.g.
NEW FEATURE: The system now supports reciting pi out to 20 decimal places. Click here for details.
I'm now documenting a change to existing functionality and want to announce this update in a similar manner. But, it's not a new feature. What would be a viable alternate term? ENHANCEMENT? SOFTWARE CHANGE? <Something else?>