The following partial list contains marks which were originally legally protected trademarks, but which have subsequently lost legal protection as trademarks due to abandonment, non-renewal or improper issuance (the generic term predated the registration).
Marks in this partial list are still legally protected as trademarks, at least in some jurisdictions, but are sometimes used by consumers in a generic sense.
Scholars disagree as to whether the use of a recognized trademark name for similar products can truly be called "generic", or if it is instead a form of synecdoche.
Writing guides such as the AP Stylebook advise writers to "use a generic equivalent unless the trademark is essential to the story".
Example: During the 2020 Summer Olympics, the BBC was called out on Twitter by the anime press and its fanbase for mistaking a monument of RX-0 Unicorn Gundam (from Mobile Suit Gundam Unicorn), installed outside Odaiba's DiverCity Tokyo Plaza for a Transformer.