id A unique ID for the element. A unique ID for the element. name Name for the group. Only usable when used as a child element to schema and ref is not used. Name for the group. Only usable when used as a child element to schema and ref is not used. ref Reference to a named group. Cannot be present when name is. minOccurs Minimum number of times the element can occur. Value can be >=0. Default is 1. Only usable with ref. Minimum number of times the element can occur. Value can be >=0. Default is 1. Only usable with ref. maxOccurs Maximum number of times the element can occur. Value can be >=0 or unbounded. Default is 1. Only usable with ref. Maximum number of times the element can occur. Value can be >=0 or unbounded. Default is 1. Only usable with ref.