code: def is30(msg):
      
  
      if allzeros(msg):
          return False
  
      d = hex2bin(data(msg))
  
      if d[0:8] != '00110000':
          return False
  
      # threat type 3 not assigned
      if d[28:30] == '11':
          return False
  
      # reserved for ACAS III, in far future
      if bin2int(d[15:22]) >= 48:
          return False
  
      return True
docs: Check if a message is likely to be BDS code 2,0
  
      Args:
          msg (String): 28 bytes hexadecimal message string
  
      Returns:
          bool: True or False