Greeting someone older than you and superiors in specific society such as company, etc., by bending low from the waist is very common in Korea. In addition, kneeling and bowing down one's head to the ground is called "jeol" and a traditional Confucian way of showing respect to parents or elderly relatives.
In Korea, a man or a woman putting an arm around or holding the hand of another person of the same sex is considered a simple act of friendship, not an act of homosexuality, unlike in other countries. Note, however, that open display of affection in public between a man and a woman is considered bad behavior.
The basic Korean diet at each meal consists of steamed rice, hot soup, kimchi, and some side dishes. Kimchi is the most popular, although there are a number of various meat and vegetable side dishes.
It is considered rude to blow your nose at the table; holding the rice bowl in your hand during the meal is bad manners. The rice bowl must be on the left, and the soup bowl must be on the right. The spoon must be placed on the left side of chopstick. Chopsticks are only laid on the left for deceased family members in Korea.
In Korea, it is customary for others to pour your drink for you and for you to pour for them. If you are offered an empty glass, let them pour your drink. Such way of drinking is an act of solidarity.
As drinking etiquette, if someone older than you offers you a drink, hold the glass with two hands and turn your head away when drinking. After finishing the entire glass, you are recommended to reciprocate by pouring for him. When pouring, hold the glass with the right hand and lightly place your left hand near your elbow as a sign of respect.
Korea was partially influenced by Chinese culture, like other Asian countries. Koreans consider 4 (pronounced "sa" in Korea) as a symbol of bad luck because it is almost homophonous to the word "death" in Chinese. Thus, many buildings including hospitals and hotels do not have a 4th floor, or the fourth floor is sometimes labeled "F" (Four) instead of 4. In addition, most Koreans do not write a name in red ink.