koreanfestivals1-6, Exercise 3: Musok and religious belonging

Model answer:

Mudang (무당): ritual specialists in Korean shamanism (Musok), mostly women, who mediate between humans and the supernatural world. Gut (굿): the rites they perform, in which they offer food and drink and entertain the gods and spirits with storytelling, song and dance.

Two kinds of gut (any two): naerim-gut, an initiation rite in which someone becomes a shaman by being possessed by spirits (only through another shaman); dodang-gut, a communal rite for the well-being of a village, held around the New Year or in spring or autumn; ssitgim-gut, a rite to cleanse the spirit of a deceased person, mainly in the south-west.

The article calls it "residual" (anthropologist Chongho Kim) because it is largely a category into which all Korean religious practices that were not Buddhist, Confucian or Christian were placed; other scholars treat it as one facet of Korean folk religion.
A survey percentage for "no religion" records how people answered about affiliation. It does not describe what they do: someone might report no religion and still hold ancestral rites or visit a temple, and the article notes that censuses do not count believers in shamanism.

Sources: Wikipedia, Korean shamanism; Gut (ritual); Religion in South Korea.