MillerCoors is currently running this Lite Beer ad, promoting the limited edition original can, and taking credit for inventing the light beer category, way back in 1973.
It is a great reminder that despite Miller’s determined and long-protracted litigation over its attempt to own the word LITE as a trademark for beer, in the end, it was unsuccessful because the misspelled word LITE was found generic — along with the correctly-spelled word LIGHT — for a type or category of beer, namely, low calorie beer.
What MillerCoors does own — as a federally-registered trademark — is the visual representation of the word LITE in the unique script to the right (with the generic word LITE disclaimed):
With the phonetically identical words LITE and LIGHT generic for low calorie beer, and part of the public domain for anyone to use, it isn’t surprising that others have gotten into the market with their own federally-registered versions of the misspelled LITE category term for beer: Falstaff Lite, Lite My Fire, Mike’s Lite, Arctic Lite, Lite is Good, and Duff Lite.
So, if you can’t legally own the category term, maybe you can take credit for inventing it. 
Marketing types, I ask you, how much is that credit worth to a brand?
Enough to make your main competitor spell the word correctly?
Trademark types, can you think of other similar examples?