org.zkoss.util.label.web.location
From Documentation
Property:
org.zkoss.util.label.web.location
Default: /WEB-INF/i3-label.properties [Since 3.6.2]
It specifies which properties file for the internationalization labels are named and located.
For 5.0.7 and later, it is suggested to use the label-location element instead, since it allows users to specify multiple properties files. In addition, the lable-location element has higher priority.