I'm dismayed to hear that the Club dress code has been relaxed to allow open necked shirts. The point about being tieless is that is exposes the neck. And, without a rule to determine how many shirt buttons should be fastened, it risks revealing part of the upper torso. While such a display may be acceptable on the squash court it is not appropriate for Club rooms particularly where ladies may be present.
The answer is to bring back the cravat; a very attractive neckwear item popular with young officers in my day. Worn with a blazer and 'ratting' cap at station sports day, it lent an air of seemliness to the occasion.
I have to say that for several months on first being commissioned I wore a cravat in bed. It was a matter setting the right tone in the presence any of the Mess batting staff who might enter my room. There were standards in those days.