The terms HDMI, HDMI High-Definition Multimedia Interface, HDMI Trade dress and the HDMI Logos are trademarks or registered trademarks of HDMI Licensing Administrator, Inc.
The actual version of HDMI 2.1 should be checked in the specifications page.
HDMI 2.0 was revised to HDMI 2.1 TMDS, and HDMI 2.1 was revised to HDMI 2.1 FRL effective from May 3, 2022.