All articles starting with R
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Ruknuddin Barbak Shah
Ruknuddin Barbak Shah (رکن الدین باربک شاہ) was sultan of Bengal of the Later Ilyas Shahi dynasty, reigning from 1459 to 1474 and succeeding his father Nasiruddin Mahmud Shah.
Rukun Negara
Rukun Negara, Malay for "National Principles," is Malaysia's national ideology, proclaimed on 31 August 1970 in response to the 13 May 1969 racial riots, with five principles including belief in God and rule of law.
Rukwa (district)
Rukwa is a region in southwestern Tanzania, capital Sumbawanga, divided into Sumbawanga, Nkasi, and Kalambo districts; 1,540,519 residents in the 2022 census, area 27,765 km², created in 1974.
Rukwa (landform)
Rukwa (landform): Lake Rukwa, a shallow alkaline outlet-less rift lake in southwestern Tanzania, in the Rukwa Rift of the East African Rift system; about 3 m deep, seismically active, Tanzania's third largest fishery.
Rula Daood
Rula Daood (רולא דאוד), born 1985 in Kafr Yasif, is a Palestinian Christian citizen of Israel, former speech therapist, and national co-director of Standing Together with Alon-Lee Green since 2019; TIME100 Next 2024 honoree and 2026 co-founder of the A Place for Us All party.
Rula Ghani
Rula Ghani (Bibi Gul), Lebanese-born Christian wife of Afghan President Ashraf Ghani, served as First Lady of Afghanistan 2014–2021, a publicly visible first lady who championed women and internally displaced people.
Rula Jebreal (رولا جبريل)
Rula Jebreal (رولا جبريل) is a Palestinian journalist and author born in Haifa in 1973, the first foreign anchorwoman on Italian national television and author of the bestseller Miral.
Rula Lenska
Rula Lenska (Róża Maria Leopoldyna Łubieńska), British actress born 1947 to Polish refugee aristocrats; breakthrough as Q in Rock Follies (1976), VO5 commercials, Claudia Colby in Coronation Street.
Rule 110
Rule 110 is an elementary cellular automaton, one of 256 rules numbered by Stephen Wolfram in 1983, proved computationally universal by Matthew Cook in 2004.
Rule 21 (California)
Rule 21 is a California Public Utilities Commission tariff setting interconnection requirements for generation and storage connecting to the state's investor-owned utilities' grids, first adopted in 1982.
Rule 30
Rule 30 is a chaotic elementary cellular automaton introduced by Stephen Wolfram in 1983, named for its Wolfram code number and used as a random number generator in the Wolfram Language.
Rule 34
Rule 34, internet adage from a Peter Morley-Souter webcomic and the 4chan "Rules of the Internet": "if it exists, there is porn of it, no exceptions." Codified 2006; companion Rule 35; now names fan-art archives and sites.
Rule 5 draft
Rule 5 Draft: annual MLB December draft of unprotected minor leaguers, dating to 1892. $100,000 fee, pick must stay on the MLB roster all season or be offered back for $50,000; famous pick Roberto Clemente (1954).
Rule 63
Rule 63, an adage from the 2007 Rules of the Internet (Rules of the Internet V.2), states every fictional character has an opposite-gender counterpart; used to tag gender-swapped fan art, cosplay, and fan fiction.
Rule against perpetuities
The rule against perpetuities is a common law property doctrine voiding future interests that may vest more than 21 years after a life in being; England and Wales now applies a 125-year statutory period, and many US states use a 90-year rule or abolished it.
Rule Breakers (film)
Rule Breakers is a 2025 Angel Studios drama directed by Bill Guttentag about Roya Mahboob and the Afghan Dreamers, Afghanistan's first all-girls robotics team, released March 7, 2025, starring Nikohl Boosheri and Ali Fazal.
Rule induction
Rule induction is a machine learning method that learns a readable set of if-then rules from labeled examples, chosen for classification tasks where the model must be transparent, as in medical classification.
Rule of 40
The Rule of 40 is a SaaS financial heuristic stating that revenue growth rate plus profit margin should equal 40 percent or more, popularized by Brad Feld in 2015.
Rule of 72
The Rule of 72 is a mental-arithmetic rule of thumb for compound interest: dividing 72 by the annual percentage return estimates the years money takes to double.
Rule of Cheng and Kang
The Rule of Cheng and Kang (成康之治) was a peaceful period of the early Western Zhou dynasty under Kings Cheng and Kang, famed for forty years without punishment.
Rule of division (combinatorics)
The rule of division, also called the division principle, is a combinatorics counting rule: count an over-counted collection, then divide by the number of times each object was counted.
Rule of four
The rule of four is the Supreme Court's custom of granting a case a hearing when at least four of the nine justices vote to hear it.
Rule of inference
A rule of inference, also called an inference rule, is a syntactic schema in logic that licenses a proof step from premises to a conclusion.
Rule of law
The rule of law, also called the supremacy of law, is the principle that everyone, including the state, is bound by laws applied by independent courts.
Rule of Rose
Rule of Rose is a 2006 Punchline psychological survival horror game for PlayStation 2, set in 1930s England, starring Jennifer and her dog at an orphanage ruled by the Aristocracy of the Red Crayon; banned in the UK, Metacritic 59, cult classic.
Rule of Saint Benedict
The Rule of Saint Benedict, also known as the Benedictine Rule, is a sixth-century Italian rule for community monastic life attributed to Benedict of Nursia, probably written at Monte Cassino.
Rule of the road (railways)
The rule of the road on railways is the convention by which trains on double-track lines keep to the left or the right, often differing from road traffic.
Rule of the shorter term
Rule of the shorter term: Berne Convention Article 7(8) rule letting a country cap a foreign work's copyright at the country-of-origin term; optional, an exception to national treatment; applied by the EU, not by the United States.
Rule of thirds
Rule of thirds: composition guideline dividing an image into a 3x3 grid, placing subjects on lines or intersections. Coined by John Thomas Smith (1797); related to, but distinct from, the golden ratio.
Rule of thirds (diving)
Rule of thirds (diving): cave diving gas planning rule, one third of breathing gas in, one third out, one third reserve; turn pressure at two thirds of starting pressure; from Sheck Exley's 1979 Blueprint for Survival.