This summary is not the rule. The rule text controls.
When you file an appeal in Oklahoma, both sides have to submit written briefs explaining their legal arguments to the court. The person appealing (called the appellant) must file their main brief within 60 days after the court receives the Notice of Completion of Record, which is the official record of what happened in the lower court case.
After that first brief is filed, the other side gets their own deadline to respond, following the same time limits set out in Rule 1.10(a). Everyone involved also needs to follow the specific filing steps described in Rule 1.10(a)(3).
The briefs cannot just say whatever the parties want in whatever format they choose. They have to follow the formatting and content rules laid out in Rules 1.10 and 1.11, which cover things like organization, required sections, and page limits. If you are working on an appeal, it helps to review those related rules alongside this one so you know exactly what your brief needs to include and how it should look.