The last appearance in the series of Yuki Shimoda just months before his death from colon cancer.
One of two times we see Peg Hunnicut, and the only time we see her in real life. The other occasion was in a dream B.J. has in "Dreams" (1980).
Here is another example of how MASH changed the time line to further a story. BJ laments to Hawkeye that on his last anniversary (approximately 11 months previously), Peg was 7 months pregnant. Assuming she had the average 9 month pregnancy duration, that would make BJ's daughter (Erin) about 10 months old when BJ was telling this to Hawkeye. In fact, the film sent to them by Peg shows Erin as a baby being bathed by Peg. However, in season 8, episode 6, BJ gets depressed/angry when he reads a letter from Peg saying that when Radar landed at the airport on his trip home from Korea, as she and Erin went to meet him, Erin went up to him and called him "Daddy" (presumably because of his uniform). Assuming Radar went home even a few weeks prior to this (if not months), Erin would've been far too young to understand/recognize a uniform being connected to her father, let alone speak any words.
Karate would not be taught in Korea as it is Japanese. Taekwondo is Korean & would be much more likely to be taught by a Korean.
The title "Oh, How We Danced" is a line from Al Jolson's Anniversary Song (originally titled Waves of the Danube).
It is also the song that Soon Chi Lu plays on the harmonica while Margaret and Hunnicutt dance.