Say you have the file META-INF/log4j.xml:

<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/" debug="false">
  <appender name="FILE" class="org.apache.log4j.FileAppender">
    <param name="File" value="test.log"/>
    <param name="Append" value="true"/>
    <param name="DatePattern" value="'.'yyyy-MM-dd"/>
    <layout class="org.apache.log4j.PatternLayout">
      <param name="ConversionPattern" value="%d %-5p [%c:%L] %m%n"/>
    </layout>
  </appender>
  <category name="com.redhat.gss.logging">
    <priority value="INFO"/>
  </category>
  <root>
    <appender-ref ref="FILE"/>
  </root>
</log4j:configuration>

And then you do this in some application code:

    System.out.println("system.out.println statement");

This logging statement will not be logged on the console, server.log, or test.log.  It's nowhere to be found.