Passive cover bonus from shield and cloak?

[Kromm]

It seems to be a FAQ, because fewer gamers than we imagined have read about Renaissance fencing . . .

A cloak has no effect on active defenses until it is taken off your back and readied in one hand, occupying that hand in a fashion that protects the arm and allows the free-hanging portion to snare weapons and distract foes. This takes one Ready maneuver for a light cloak, two Ready maneuvers for a heavy one. At that point, the cloak provides DB 1 (if light) or DB 2 (if heavy) against attacks from the front or the cloak side, and permits a Block defense equal to (Cloak/2)+3.

A cloak on your back does nothing useful beyond keeping you warm and making you look cool. Its DR protects it, not you, because it's just too thin. There are rules for cloaks that do offer DR in GURPS Dungeon Fantasy Denizens: Swashbucklers. These are heavier and more expensive, give a skill penalty, and are kind of ugly. They do last longer, though.

A cloak never provides any active defense benefits against attacks from the opposite side or the rear, no matter what advantages you have.