in the 19th century, the custom of sending valentine's cards became very popular. the cards usually have pictures of hearts or flowers and contain some sort of poem, message, or code. codes and simple messages give some people the courage to show their true feelings to the person they love. today, some people still use mysterious codes to show their love. people can use newspapers to give a coded message to their loved one, giving other readers a view of the couples' intimacy with one another. sometimes they will give each other chocolates.