I don't understand this part of the Robust Porter description for the BJCP guidelines:
http://www.bjcp.org/2008styles/style12.php#1b
"... it may be distinguished from Stout as lacking a strong roasted barley character. It differs from a brown porter in that a black patent or roasted grain character is usually present..."
What is the difference between "roasted barkey" and "roasted grain" flavors, how can it lack one but have the other?