Chivalry can be defined as the medieval system, principles, and customs of knighthood, the qualities idealized by knighthood, such as bravery, courtesy, honor, and gallantry toward women.
The act of placing a jacket over a puddle, pulling out a chair for a lady or opening a door, these are just a few chivalric acts. Are these "codes" still followed? During the middle Ages a lady was treated with respect. Chivalry was basically a way of life. This is nothing like modern society now. Yes, there are a few gentlemen out there but Chivalry is not as important as it was five hundred years ago.
During Mid-evil times, knights were to be courteous to women. Do whatever they could for them. Men would battle over women or defend their honor. Men would fight over women to prove their love to them. .
Another part of chivalry was integrity and other feelings of that nature. Not only were men courteous but also they were courageous. These men would put their lives on the line to become a night. This took integrity, courage and pride. Integrity is defined as steadfast adherence to a strict moral or ethical code. This goes back to the way women were treated and why they were treated this way. Because men were brought up with integrity, they followed the "moral code", which was to respect women. It is easily put when said "would you treat your mother that way" due to the fact a son would always respect his mother.
Times have definitely changes over a five hundred year period. There are still a select few who still practice chivalry, not exactly how it was practiced in the middle ages. But it's close.