My design would remove all ambiguity, by having different rules for describing port vs. device capabilities.
1. HDMI ports should be described as "HDMI X.XX Compatible". This indicates that the ports themselves (and the device that contains them) will work when connected to any other HDMI X.XX device, and that the description is of a port.
This is the low bar on 2.1 devices. Their ports will sensibly negotiate optional features with other HDMI 2.1 devices.
2. HDMI devices should be described as "Full HDMI X.XX" or "Limited HDMI X.XX up to [limitations]" to distinguish devices that support all features of X.XX that apply to the device, or have applicable limitations. (Audio devices would not be considered "Limited" by non-applicable features such as image resolution.)
The ""Limited HDMI X.XX up to ..." disclosure would need to be prominently displayed in any description. One place where all limitations can be found.
Limitation phrases (like "up to 4k resolution") would have standard wording supplied by the HDMI standards body.
Additional references to HDMI versions, such as product listing titles, can be shortened to "Limited HDMI X.XX" without any limitations listed. So all limitations listed, or none, to avoid any confusion.
My design would be HDMI 3.Y where Y is a variable-length Base32 encoding of the value of a bitmask representing the presence of the underlying features of an HDMI port/cable/device.
This is terrible. You expect an average consumer to start converting base32 to binary to check what features their cable support? I mean I'm all for educating the public but this is just completely unreasonable
1. HDMI ports should be described as "HDMI X.XX Compatible". This indicates that the ports themselves (and the device that contains them) will work when connected to any other HDMI X.XX device, and that the description is of a port.
This is the low bar on 2.1 devices. Their ports will sensibly negotiate optional features with other HDMI 2.1 devices.
2. HDMI devices should be described as "Full HDMI X.XX" or "Limited HDMI X.XX up to [limitations]" to distinguish devices that support all features of X.XX that apply to the device, or have applicable limitations. (Audio devices would not be considered "Limited" by non-applicable features such as image resolution.)
The ""Limited HDMI X.XX up to ..." disclosure would need to be prominently displayed in any description. One place where all limitations can be found.
Limitation phrases (like "up to 4k resolution") would have standard wording supplied by the HDMI standards body.
Additional references to HDMI versions, such as product listing titles, can be shortened to "Limited HDMI X.XX" without any limitations listed. So all limitations listed, or none, to avoid any confusion.
Done! Next problem, Internet? ...