The phrase "primary rule" refers to a basic or most important rule that guides behavior or actions in a particular situation or setting. It is a fundamental or initial guideline that is crucial to follow. Full definition
Performance is measured using 44 indicators across eight primary rule of law factors, each of which is scored and ranked globally and against regional and income peers: Constraints on Government Powers, Absence of Corruption, Open Government, Fundamental Rights, Order and Security, Regulatory Enforcement, Civil Justice, and Criminal Justice. (worldjusticeproject.org)
The new primary rules create an open congressional primary (voters can cross party lines and vote for whomever they choose) however, only the top two vote getters advance to the November ballot. (thirdpartypolitics.us)
New York's Republican primary rules allocate three delegates to the winner of each of 27 districts if he takes more than 50 percent of the vote. (mobile.nytimes.com)