SpringSchemaProvider already has cached structures containing: a) namespace URIs for all handlers (both spring "core" as well as third-party - collected from module classpath) b )schemaLocations for all valid namespace schemas (also collected from classpath) This data could be used by the XML editor to provide additional completion variants for: a) namespace declarations + xsi:schemaLocation "keys" b) xsi:schemaLocation values This is a minor feature, but is seems a waste not to use the data when it's already available. I assume this would require an additional extension point (similar to com.intellij.xml.schemaProvider)?