In the Conversational Flows object, the User inputs are associated to variables (which have to be defined in the variables tab of the object).
For any of these variables who are associated to a User input, if the Collection property (IsCollection checkbox) is set to TRUE, and the Match With Entity property (at the User input) is set to TRUE and the Entity property is set to a non empty value, it means that more than one entity value can be recognized from the user's input.
Since GeneXus 16 upgrade 10