This summary is not the rule. The rule text controls.
Here's a plain English summary of this rule.
The Court of Appeals officially takes over a case on a specific date. That date is when the Clerk notes "Notice of Completion of Clerk's Record" in the case file. Until that note is made, the trial court technically still has the case.
But this doesn't mean nothing can happen before that date. The Court of Appeals can still step in early if needed. For example, if someone needs to file certain motions, like requests covered under Rules 18 and 39, the appeals court can handle those even before it fully takes over the case. This lets urgent matters move forward without waiting for the official paperwork to catch up.
For people involved in a case, this means the appeal process has a clear starting point on paper. But it also means you're not stuck waiting if something time-sensitive comes up before that official date arrives.