WML files – and any .nrd files used by a WML menu structure – must be stored in the printers E: memory location. While the files are first being transmitted to the printer, they should not be processed by the printers ZPL formatting engine. This can be done by using the CISDFCRC16 command. This command allows content to be written directly to the E: memory location, without being processed by the printers ZPL formatting engine. By using the CISDFCRC16 command, WML content can be transmitted to the printer via the Serial, USB or Parallel ports.