in src/main/java/org/apache/log4j/Level.java [156:175]
Level toLevel(String sArg, Level defaultLevel) {
if(sArg == null)
return defaultLevel;
String s = sArg.toUpperCase();
if(s.equals("ALL")) return Level.ALL;
if(s.equals("DEBUG")) return Level.DEBUG;
if(s.equals("INFO")) return Level.INFO;
if(s.equals("WARN")) return Level.WARN;
if(s.equals("ERROR")) return Level.ERROR;
if(s.equals("FATAL")) return Level.FATAL;
if(s.equals("OFF")) return Level.OFF;
if(s.equals("TRACE")) return Level.TRACE;
//
// For Turkish i problem, see bug 40937
//
if(s.equals("\u0130NFO")) return Level.INFO;
return defaultLevel;
}