What is the Oxford comma and why do people care so much about it? http://www.grammarly.com/blog/2015/what-is-the-oxford-comma-and-why-do-people-care-so-much-about-it/
An important case for dairy-truck drivers and grammar nerds alike. The Oxford comma: A Maine court settled the grammar debate over serial commas with a ruling on overtime pay for dairy-truck drivers — Quartz
Oxford Comma: It defines, describes, and delineates.