Example combining details and a definition list (dl)
The example below wraps the details element with a dl element, while the dt element is inside the summary element;
the summary element is followed by dd elements. For correct rendering, the dt element needs the CSS declaration
display: inline.
Fork
(Traffic) A fork (literally "fork in the road") is a type of intersection. When a road splits, the main road steers to the left or right, depending of what side you drive on, and the smaller road heads straight. (Source: Wikipedia: "Intersection (road)".)
(Chess) A knot is a move that uses one piece to attack two or more of the opponent's pieces simultaneously, hoping to achieve material advantage, since the opponent can only counter one of the two threats. (Source: Wikipedia: "Chess tactic".)
Skewer
(Cooking) A skewer is a thin metal or wood stick used to hold pieces of food together. (Source: Wikipedia: "Skewer".)
(Chess) A skewer is a move which attacks two pieces in a line, similar to a pin, except that the enemy piece of greater value is in front of the piece of lesser value. After the more valuable piece moves away, the lesser piece can be captured. Queens, rooks, and bishops can perform the skewer. (Source: Wikipedia: "Chess tactic".)
Findings:
In Google Chrome 20.0.1132.47 and Comodo Dragon 20.0 (based on Chromium 20.0.1132.47), both on Windows 7 32-bit,
only the first summary gets focus; the link inside the second (closed) details element does not get focus.
Adding open="open" to the first summary element does not make a difference.
Adding open="open" to both summary elements does not make a difference, either!
Nor the second summary element nor the link inside it receive (tab) focus.
Using open instead of open="open" gives the same results.