What is this ROMEO club from the book the greatest generation

The ROMEO Club, which was initially started by John Caulfield, a retired high school principal, began in Massachusetts. The group of "retired old men eating out" was made up of the guys from Kerry Corner, which was an Irish working class neighborhood. They grew up together, played together, and joined the Navy together after the bombing of Vietnam. They met at various diners in Harvard Square (Cambridge). They were all war veterans.