When the ShowByWarehouse property is not set for the control, behavior will default to the setting "Display Quantity Subtotals by Warehouse" in the Quantity Settings tab of the Site Manager > Catalog Configuration screen.
When the property is set, the value specified will override the site configuraiton setting.
Important Note:
It is not recommended that sites display inventory quantity by warehouse when utilizing the CyberStore inventory buffer feature. Current business logic will display quanties by each warehouse, with each quantity being reduced by the buffer amount.