This document defines and discusses short messages. It notes that short messages are brief written communications sent because people cannot meet directly. They are easy for everyone to compose. Short messages have clear addresses, simple messages, and are easy to understand. They are used to give or request information, ask permission, apologize, or invite. When composing short messages, one should pay attention to who sent it, who it's for, the information and purpose, and the relationship between sender and receiver. There are different kinds of short messages including memos, SMS texts, and telegrams.