I've never thought about this until now but I vaguely recall that the Delta shield was chosen for it's meaning (forget exactly what is was and I don't mean why they chose the Enterprise symbol for Starfleet, I mean originally why it was chosen in 1966) but when it came to designing the badge for the TWOK uniforms they kept the delta but put it in front of a rounded rectangle with some kind of rectangle with the sides pointed inwards and then a small dot at the top right corner. I was wondering if there was meaning behind this or if it was just a random choice?