There are no RAF versions of the F-15E, no one else in the world, but the USAF has them. And these are USAF textures. RAF Lakenheath is a joint American/RAF AB. The United States regards RAF Lakenheath, England as Lakenheath AFB, USA. Thats why the Eagle here has LN on it's tail. The squadron it belongs to is an American Air Force squadron, flown by American pilots. The Strike Eagles I most remember had SJ- for Seymore Johnson AFB, North Carolina- on their tails instead. It's just a simple little identifier code that helps pilots and such quickly tell which base a plane is from.
Not trying to be nasty but some pepole seemed confused. Is everyone clear on this, now...?