"Speak as little as possible about yourself."
Our culture is steeped in social media venues which constantly encourage us to speak about ourselves. We can barely imagine a society where it would be considered impolite to volunteer information about our current "personal status." In a world where seemingly everyone is self-broadcasting, most have forgotten what was once a firm rule in polite society: Do not speak of yourself unless asked.
A vital part of a mindset distinctly focused on others instead of self, this attribute distinguishes a lady from other women. When consistently practiced, this gracious self-restraint will always be endearing and charming in a self-absorbed world.
Principle: A lady does not volunteer information about herself, but only speaks of herself when asked.
Art: Young Women Talking, Renoir, 1878