It's NEW DAWN operating a regular B752 from JFK to EGSS and return. I believe they're a business class only outfit. Perhaps 'Nude-on' would be a more interesting callsign; it would certainly attract the attention and have us folks putting down Page 3!
As regards callsigns, us oldies just had to learn them. We used to have progress tests at the College of Knowledge each week on our initial course and then learnt them as we went along. These days the 'kids' are helped by the company RT callsign being printed on the top of the strip above the 3 figure designatior and trip number. My god, they have it easy these days!
Come on guys, how many old 2 letter ones can you remember besides BA and all the easy ones?