"primary rules" is a grammatically correct phrase and can be used in written English.
It refers to the most important or essential rules in a particular context. Example: In order to succeed in this job, it is important to follow the primary rules of punctuality and professionalism.
John M. Broder (NYT) THE STATES PRIMARY RULES AT ISSUE Citing a recent Supreme Court ruling, the head of the Democratic Party in Washington State has threatened to go to court unless state election rules are changed before the Sept. 19 primary to prevent a "blanket primary".
And the state's blanket primary system, under which a voter may select any candidate on the ballot, is on its last leg anyway: because of a United States Supreme Court ruling this year that invalidated a similar system in California, the primary rules will almost certainly be different in future elections here.
Mr. Romney is also helped by California's complex primary rules.
There are two primary rules in locksport, he emphasized.
The state judge called the primary rules reasonable.
My certainty is based on the flagrant disregard for one of the facility's primary rules.
It's possible that she would have won if the Democratic Party had more rational primary rules.
The Democratic primary rules also require petitions, but they are somewhat less complicated.
She also rejected his criticism of the party's primary rules, noting they were adopted nationwide in 2014.
Asked why the Republican legislature changed the primary rules for this particular election, Susan MacManus, professor of government at the University of South Florida, said, "Because they could".
Virginia's Democratic primary rules allow independents to cast ballots, which could work in Mr. Obama's favor, and the city of Washington has a black majority.
