This patch includes an entirely new on-line game mode for Half-life: Opposing Force called Capture The Flag. This patch will also update Half-Life: Opposing Force to version 1.1.0.0 to be compatible with Half-Life version 1.1.0.0.

Here is the full description sent along by GearBox. You can grab the 12meg download here. Remember, you must have the Half-Life expansion pack to use this.