code: public static final String getShortName(int scriptCode){
          return UCharacter.getPropertyValueName(UProperty.SCRIPT,
                  scriptCode,
                  UProperty.NameChoice.SHORT);
      }
docs: Returns the 4-letter ISO 15924 script code,
  which is the same as the short Unicode script name if Unicode has names for the script.
  Returns "Mlym" given MALAYALAM.
  
  @param scriptCode int script code
  @return short script name (4-letter code)
  @throws IllegalArgumentException if the script code is not valid