I haven't heard of these terms in years and years. But yes I do remember them. Going to high school in the 50's, particularly at Washington High, here were guys and gals that we knew to be BART. I have never heard the terms "Barts" used in reference to these kids. Pachukos was another term. Typically the guys sported longish duck tale combed hair, black jeans (Big Bens) with key chains hanging off their belts. The girls sported huge hair, back combed to death! Long earrings and both the guys & gals sometimes wore huge crosses around their necks. I remember being a yell leader at Presidio Jr High and attending a game out at the Soccer Fields in the Park when I was approached by some Pachuko girls who actually had razor blades embedded in their shoes. I had to run to get away from them.
The "Ivy" look was very different. Guys sported neat khakis, button down shirts, and nice windbreaker jackets. Their hair was short and neat. Their khakis had the buckle on the back (so did the girls). They also wore buck or suede saddle shoes. The girls typically wore Rosenbloom suits, cashmere sweaters, white buck or brown & white Spalding shoes. The skirts were just above the ankle then, and the socks at one point were rolled down to just above the shoes. This style changed over time.
Whew, that was a step back.