Coat cards, also known as calling cards or visiting cards, were popular in the 18th and 19th centuries as a way of announcing one's presence to a homeowner. Today, they have largely fallen out of use, but the concept of leaving a calling card still exists in some circles. Synonyms for coat cards might include introduction cards, personal cards, or social cards. In a more professional context, they might be called business cards or networking cards. Regardless of the name, the purpose remains the same: to make a good impression and facilitate continued communication and connection with others.