This summary is not the rule. The rule text controls.
The Board of Bar Examiners gets to create its own rules for how it operates and how it handles the process of testing and admitting people who want to become lawyers. This covers things like how exams are given, what steps applicants need to follow, and other details about the admission process.
But the Board can't just put these rules into effect on its own. The Oklahoma Supreme Court has to review and approve them first. Once the Supreme Court signs off, these rules carry the same weight as if the Supreme Court itself had written them.
For anyone applying to become a lawyer in Oklahoma, this means the specific steps and requirements you'll follow come from the Board of Bar Examiners, but they're backed by the full authority of the state's highest court.