While looking for the full name of Robert Gordon ‘Bob’ Hawthorn 550929, which became a pow when his plane, Halifax II W1216 – 103 Squadron, crashed in Belgium the following remarks were noted on his entry in the AIR78/73 part 2 file an ‘F’, which stands for Class F Reserve and ‘ Boy Entrant U/T W’Less op… The dotes are for 3 letters which I can’t read.

What does this text refers to ?

Many thanks in advance and best regards