Also, that someone without contracts would probably need to call it different than "HDMI", because the term itself is trademarked and only licensed to Members (like "Wi-Fi" and "Bluetooth").
So a different term would be needed (like "WLAN" or "BT" is used by non-members)
As much as we can talk about HDMI here, as it's a name in the public domain, wouldn't someone else be able to use that kind of speech to make a "HDMI-compatible" implementation? "IBM compatible" seemed to be a designation, in the day, that didn't run up against legal trouble?
Maybe that's what you already meant by "calling it different than".
Trademark law always hinges on the question if a reasonable consumer with reasonable knowledge could be expected to distinguish those trademarks or not.
HDMIY would most probably not fly, HDIY would probably.
not yet a lawyer, though.
edit: I'm also fairly certain that the HDMI forum would fight HDIY tooth and nail, so whoever goes public with that absolutely needs deep pockets.
I am pretty sure that the term being a trademark doesnt stop me from mentioning it when describing compatibility. Do you think apple could sue me if i release a program and say "This software is compatible with macOS"? As long as I am not impersonating them, using the Logo etc., they probably can not stop me.
Of course they could sue you, and so could I. Neither of us would win, though. I because I don’t hold the trademark, they because they explicitly allow you to do that.
“2. Compatibility: Developers may use Apple, Macintosh, iMac, or any other Apple word mark (but not the Apple Logo or other Apple-owned graphic symbol/logo) in a referential phrase on packaging or promotional/advertising materials to describe that the third party product is compatible with the referenced Apple product or technology, provided they comply with the following requirements.
a. The Apple word mark is not part of the product name.
b. The Apple word mark is used in a referential phrase such as “runs on,” “for use with,” “for,” or “compatible with.”
c. The Apple word mark appears less prominent than the product name.
d. The product is in fact compatible with, or otherwise works with, the referenced Apple product.
e. The reference to Apple does not create a sense of endorsement, sponsorship, or false association with Apple or Apple products or services.
f. The use does not show Apple or its products in a false or derogatory light.”
Ok sure, they could sue me, but they would not win. Do you think they would win if they had not explicitely allowed that usage? I don't have a source but I am very sure that you can't stop someone from using your trademark, the trademark only protects the use in business, i.e. me selling a OS called "macOS". Just mentioning the name is no trademark infringement.
I'm pretty sure your legal analysis here is overly-simplistic, but we don't need to get into that.
Going back to the original topic, if somebody is trying to release open source drivers for HDMI (or a protocol compatible with HDMI), obviously trademark infringement is a possibility since both are in the exact same business. So even if you're right (which I don't think so), your argument doesn't apply.
Being in the same business does not make it trademark infringement. Ubuntu could also advertise "This OS can run software for Windows by using WINE" without infringing on Microsoft's trademark, because they aren't acting under the trademark. Trademarks exist so you can't sell your product under the established name of another company and profit from their reputation or ruin it by selling bad products. Just mentioning the name to state a fact is not forbidden. Just writing a driver and distributing it with the claim "HDMI-compatible" is not trademark infringement. They problem in OP's article is that AMD has a contract with the HDMI Forum.
Do you think it would be trademark infringement if I code a HDMI driver and then publish it on GitHub with the description "This is a HDMI-Compatible driver"?
Saying "compatible with <trademark>" is if anything one of the best established examples of nominative use. Like PC-compatibles which IBM had no way of stopping. Apple could try to sue, but the case would get dismissed immediately.
Any time I've seen that on actual packaging, it does come along with "<trademark> is a registered trademark of <corporation>". Though usually those same boxes use official published logos from <corporation>.
I checked and found this info from the Wi-Fi Alliance [0]:
> Select brands and logos are offered license free and intended to be used widely throughout the Wi-Fi ecosystem by Wi-Fi Alliance members, non-members, industry partners, media, and analysts to describe products, technology, network deployments, and operating system support.
It sounds to me like anyone could use the trademark "Wi-Fi", since it's listed in the freely available ones.
Trademarks are there to protect consumers from dishonestly represented goods. If I buy some display tech marketed as "HDMI-compatible" but unlicensed, and it works with my other HDMI equipment (say, its maker reverse-engineered the HDMI spec), no one has been defrauded.
So a different term would be needed (like "WLAN" or "BT" is used by non-members)