Liquid XML Studio supports the Oasis XML Catalog standard, these catalogs provide mappings and re-directions, allowing namespaces to be mapped to file locations, file URLs to be re-directed to locally cached resources. Some schemas even use URLs that are non-standard and can only be resolved with the additional information contained within an XML Catalog (see many of the OASIS standards).

If an error occurs loading an XML Catalog then it will be shown with an error icon  and hovering over the entry will provide a tooltip with the error.