My informant is the daughter of immigrants from Bangladesh. She told me about a folk belief from when her mother was a teenage girl in her home country.
Occasionally, one will find small white marks on their nails. According to this folk belief, this mark appearing on a girl’s nail means that she will receive a new dress. This has particular significance around the Muslim holiday of Eid, where it is customary to wear many new outfits when visiting different relatives. This is also significant in Bangladesh because there is more widespread poverty and new dresses are more difficult to come by. Because of these reasons, young girls in my informant’s mother’s neighborhood would become ecstatic when they discovered white markings on their nails.
This is interesting to think about when learning of the scientific reasoning behind these white markings, because all they indicate is that there was previous injury to the nail bed. However, folk beliefs are often used to explain things that are not widely understood, and most people are not aware of the true meaning of these marks.