It may result in a slapped wrist to resurrect this topic, but I don't think starting another one would attract the people who contributed to this topic in the first place...
I just noticed on Memory Alpha that it gives a reason for the seeming confusion for Spock's rank:
I just noticed on Memory Alpha that it gives a reason for the seeming confusion for Spock's rank:
Spock, as well as a few other lieutenant commanders seen in The Original Series (such as Benjamin Finney), are very clearly called Lieutenant Commander while wearing the insignia of a Commander. While sometimes viewed as a costumer error, the late original series costume designer William Ware Theiss stated in interviews that this was very much deliberate and that the practice of Lieutenant Commanders wearing the insignia for a full Commander mirrored the US military concept of "brevet" or "spot" promotions given to officers due to the nature of their billets.