국룰

Korean

Usually analyzed as a blend of 국민(國民) (gungmin, “citizen”) +‎ 룰 (rul, “rule”, from English rule).

Romanizations
Revised Romanization^?	gungnul
Revised Romanization (translit.)^?	guglul
McCune–Reischauer^?	kungnul
Yale Romanization^?	kwuklwul

국룰 • (gungnul)

(neologism, slang) an unwritten rule or unspoken rule, usually lighthearted or non-serious [mid 2010s]
- 2021 February 6, “주4일 근무해도 회사 안 망합니다 [ju4il geunmuhaedo hoesa an manghamnida, a 4-day workweek won't ruin companies]”, in Weekly Dong-A‎^[1]:
  지금 은 달력 의 ‘파란 날’과 ‘빨간 날’에 쉬는 것 이 ‘국룰’로 여겨지 지만, 한국 사회 에 주 5 일 근무제(주 5 일 제)가 정착된 건 20 년 도 되지 않는다.
  Jigeum-eun dallyeog-ui ‘paran nal’-gwa ‘ppalgan nal’-e swineun geos-i ‘gungnul’-ro yeogyeoji-jiman, Han'guk sahoe-e juoil geunmuje(ju oilje)-ga jeongchakdoen geon isimnyeon-do doeji anneunda.
  At this point, the notion of [employees] getting their weekends off is [well-accepted to the point of being] this unwritten rule. However, [one should put in mind that] it has been less than 20 years since the 5-day workweek has become the standard in Korea.
(neologism, slang, by extension) an obvious choice; something obvious; a trend [mid 2010s]
라면 에는 김치 가 국룰이다.
Ramyeon-eneun gimchi-ga gungnur-ida.
Ramen with kimchi is amazing.
(literally, “Ramen with kimchi is an obvious choice.”)