The reason why the RAF designation will not be found in contemporaneous records is explained in the very first sentence of the document.
United States military units assigned in the United Kingdom (UK) during World War II had to avoid any direct connection with specific geographic locations for security reasons . Most United States Army Air Forces (USAAF) units therefore identified their location with a "station number ." Although each USAAF installation in the UK was named--generally after the nearest railway station--official correspondence and unit histories most often employed the station number