This is probably related to whether one should capitalize Internet or not. I am looking for the correct spelling of wifi when referring to a wireless connection to the Internet. I want to tell the users of my iPhone app that they cannot use their cellular network to watch the HD videos.
If I use the capitalized and hyphenated version as seen on Wikipedia, will I be referring to the Wi-Fi brand rather than the concept of wifi?
"Wi-Fi" is a trademark of the Wi-Fi Alliance and the brand name for products using the IEEE 802.11 family of standards.
Some dude on Meta.stackoverflow made this claim with no explanation:
WiFi" is a bit better than "wifi" as it asserts the etymology, compare history of usage of "hifi" from which it derives. – Steve-o Aug 29 at 3:59