Courtly, chivalric, and gracious

At the root of the class system is the divide between the regime of scarcity and the regime of abundance. 

For the lower classes the regime of scarcity rules while the upper classes are expected and expect of themselves to operate under the regime of abundance. Hence, honor is not expected of someone from the lower classes, where churlish behavior is the norm, but it would be dishonorable for a gentleman not to keep his word and not to act in a courtly, chivalric, and gracious manner. It would be understood as a stain on his class.