Out-of-character discussion.
I have gotten into the habit of bolding words and phrases in my posts that I think are noteworthy. Usually, they're things that are key to the mechanics, like who is targeting whom with what, and what that outcome is. If it's annoying, I can stop, and no one else is obligated to do it.
The marks the knights apply are nothing fancy, just the standard: -2 any attack that doesn't include the marking creature as a target.
With two dragonborn on the field, I'll note that the knights are positioned in such a way that it would be impossible to catch them both in a close or area attack without targeting Sietnyas.
I have some informal ways of stating positions, when the exact number of squares isn't known or doesn't matter too much. I can't say I didn't steal this from some other game.
Adjacent means adjacent.
Engaged usually means adjacent and implies that blows have been traded or are about to be.
Near or close means within a move. If the slowed condition or difficult terrain is in play, this might need further clarification.
Far means more than a move away, but probably not two moves away. Again, certain types of effects might mean some clarification is in order.
I find 4th Edition situations don't usually get further apart than that, but if they do I'll make it as clear as I can.
Remember that a flanked character needs to move at least 2 squares not to be adjacent to at least one of them.
Take it away, Drake!