GWT package structure question?

I was just wondering what is the significances of the com in most GWT modules that people make. Eg:

com.allen_sauer.gwt.log.gwt-log-TRACE

Is it to do with like .com domain or something? As I named my package ie.[company].[appName] ie for Ireland.

Also when exporting your GWT project as a JAR to use in other projects开发者_JAVA百科, is there anything special needing to be done to get it to work. Besides the inherits in the xml? As I still get this error.

Unable to find 'test.gwt.xml' on your classpath; could be a typo, or maybe you forgot to include a classpath entry for source?

This is from the Java world. When naming packages you are advised to use your reverse domain name as the base name of all your packages. So if your domain name is example.com then your packages should be com.example.something.

This ensures that there are no name space clashes when your code is used with other libraries.