This document discusses various types of etiquette for the 21st century, including mobile phone, social media, environmental, and citizen etiquette. It provides guidelines for proper mobile phone use in public settings like avoiding calls in libraries and keeping the volume low. For social media, it recommends thinking carefully before posting photos of yourself or others and avoiding posting when hungry, angry, lonely or tired. Environmental etiquette focuses on reducing paper waste and saving water. For citizen etiquette, it encourages battling corruption and voting. The document concludes by emphasizing the importance of various technologies and resources like electricity.