I use this knot to attach my kite to my flyinglines. I'm sure this knot has another name also, but my friend Mårten gave it the name "Stockholm knot" because he was in Sweden when he discovered it.
On the end of my flyinglines I have a loop like this with a smaller loop att the end. I leave you with the choice of which knots to use to make your loop.
On the bigger loop I then make a lark's head.
I make a knot on the end of by bridle line and thread it through the lark's head.
Then I pull both ends of the bridle line and on the flyingline to tighten the knot.
To open the knot I pull both ends of the bridle line and the small loop on the lark's head.