The Holds block is located in the exceptions drawer of the Blawx toolbox.
The Holds block is used to query whether a conclusion was reached according to any section of the rules, and that conclusion was not overruled.
The Holds block is a statement block which can be stacked with other statements. It accepts an internal statement stack, which should be a single statement block, which is the conclusion that is being sought.
Even if you are not using exceptions, the combination of "According To" and Holds blocks can be used to insert information about the source of your rules into your natural language explanations.