Ultimate Comma

Commas are required after the first, second, third, and penultimate items in a list.

Ultimate: 

a : last in a progression or series : final
their ultimate destination was Paris

b : eventual
they hoped for ultimate success

c : the best or most extreme of its kind : utmost
the ultimate sacrifice

d : most remote in space or time : 

Comma: 

a punctuation mark, used especially as a mark of separation within the sentence