I have difficulty to understand highlighted statement within below pega help document, can anyone explain the meaning by giving some example?

What does "associates a ruleset" mean in terms of the rule resolution? Trying to understand how branch rule set works in another discussion here.

https://community.pega.com/sites/default/files/help_v719/procomhelpmain.htm

Notes on branch merging

In Pega 7 Platform, branch identifiers (their names) are system-wide. They can be used by anyone that has a compatibly configured application. However, if another team creates a branch ruleset based on a ruleset that is not in your application or one of its parents and selects a branch identifier that you are using in your development application, the system does not associate that branch ruleset with the branch and associates a ruleset that only it can see in their application. The system displays a warning in the application rule. In this situation, you can either add the missing dependency ruleset to the correct location in your application stack or negotiate with the other team to have them move their work into a new branch for their own use.