The branch ruleset is associated with a branch based on your selections in the New form for creating a ruleset.
The development application must have at least one branch before you create a branch ruleset. A branch ruleset is branched from a ruleset in the main (base) application or any of its built-on applications. The team determines which ruleset contain the rules they expect to modify for a planned enhancement and creates the branch ruleset based off of those rulesets.