I am a little thing with a big meaning.
I help everyone.
I unlock doors, open hearts, and banish prejudice.
I create friendship and goodwill.
I inspire respect and admiration.
I violate no law.
I cost nothing.
Many have praised me; none have condemned me.
I am pleasing to those of high and low degree.
I am useful every moment.
Who am I?
I am courtesy.
by Author Unknown