The company's policy mandates that employees carry out file transfers using encrypting traffic protocols. There is a suspicion that some employees may disregard this policy and continue to perform file transfers using unencrypted protocols due to resistance to change. To investigate this, a network sniffer has been strategically placed to capture traffic from the laptops used by employees in the data ingest department. To identify unencrypted file transfers by examining the captured traffic in Wireshark, which command can be used as a display filter?