The List step allows the user to select a pre-defined value from a list. This could be anything from selecting which shipping agent to use during a picking routine to specifying a reason for moving or discarding an item.
AX
In AX the header is specified in the class Mob_GetReferenceData. The most commonly used method is addDefaultWarehouseElement(..) but there is multiple used..
Alternative use addHeaderConfigurationElement(..) with type #InputTypeList.
You must specify a datatable to use.
The valid values must either be specified by a list or as a reference to a datatable.
The datatable is also created in class Mob_GetReferenceData, look at addWarehouse2ReferenceData(..) - called from process(..), the method created a list with data - ready to be used in the controls in Mobile WMS.