The T-bar design was a progression from a design revision of the Enterprise uniform. Now keep in mind these images are just to illustrate the design progression, they aren't intended to represent "in universe" uniform designs. The T-bar was based on the Enterprise uniform: I thought the design could use a bit more color so I added these torso bars. I ended up removing the shoulder bars because we've has so many years of shoulder patterns with TNG era Trek, and I wanted something different. With the lack of shoulder bars I thickened the torso lines. It just seemed natural to bring the two sides together in the middle. With this revision the "I-bar" was born. This next revision came along just to bring variety I suppose. I can't recall what form the uniform was in before this next revision. It could have been a jumpsuit or something else. However, I really like the Movie Era designs, so I created a variety of based off the "Monster Maroons." With the jacket the lower bar got in the way. It seemed useless to have a skinny little bar along the bottom of the jacket. Thus the lower bar was removed and the design became the "T-bar." I also decided to outline the bar in black rather then have a colored bar on the jacket. So that's the story. Now that I've been thinking I'm going to do another revision. I want it to look a bit more futuristic. I think I'm going to take some design ques from the movie "Oblivion." I really like that design.