Customizing server messages
Language-specific message settings for Liferay can be tuned in files within the "content" directory within portal-impl.jar in the main lib directory.
In practice, it may be possible to tune these elsewhere to facilitate upgrade, etc.
The layout of the language files is as follows:
With defaults in the first file, overwritten in the language-specific file and then overwritten further in the region-specific file last of all.
An example might be that most messages in English are written in Language_en.properties in US English, but when the server sees a locale of en_GB for UK English, then overrides from Language_en_GB.properties will be used, such as "kilometer" to "kilometre", etc.
Languages accepted by Liferay can be configured in portal.properties/portal-ext.properties, with the accepted list expanded or reduced as necessary.
See [http://www.liferay.com/web/guest/community/wiki/-/wiki/Main/Languagedisplay+customization | Liferay language customization documentation] for further information.
At the moment, any amended Language files need to be put into a modified JAR file on the server, and the server restarted for changes to take effect.
Next step is to find a way to make these changes without putting them into a new JAR file. Server restart will still be necessary.