You don't HAVE to. It's not a law, but invitations will be hard to come by if you do not know how to comport yourself in polite society.
netiquette
Keep your observations to yourself unless they are doing something illegal , or alert your hostess if a common food item [ shared ] has been contaminated.
Etiquette 101 - 2004 Wedding Etiquette was released on: USA: 17 August 2008
Etiquette 101 - 2004 Dining Etiquette was released on: USA: 16 December 2006
Etiquette 101 - 2004 Etiquette for Everyone was released on: USA: 19 November 2005
Charlotte Ford has written: 'Twenty-First-Century Etiquette' -- subject(s): Etiquette 'Etiquette' -- subject(s): Etiquette
etiquette is what, and protocol is when
See related answer :How did Etiquette begin.
These mushrooms are quite etiquette!
Etiquette is the correct spelling.
Backstabber Etiquette was created in 2002.
Go to www.usga.org/playing/etiquette/etiquette for a very thorough explaination.