Sentence:  A list of new titles was manufactured as follows: "Ensign", "Lieutenant", "Flight-Leader", "Squadron-Leader", "Reeve", <WSD>"Banneret</WSD>", "Fourth-Ardian", "Third-Ardian", "Second-Ardian", "Ardian", "Air Marshal". […O]ne may regret “<WSD>Banneret</WSD>”, which has a flavour and associations, more especially as the leader of a formation in the air went into battle flying a streamer which formed a rallying mark as did the banner of the knight for his vassals. 
Meaning of the word marked with <WSD> tags:  A (proposed) but (unadopted) senior commissioned (rank) of the Royal Air Force equivalent to (group captain).