@a1ba the issue is with them not using the numbers, but the marketing terms. 720p, 1080p, 1440p, 2K, 4K, 8K are all precisely defined (precisely enough, at least). HD, FHD, QHD, idkHD aren't.
Also, if we're talking about video resolutions, there's a very important difference between 720p and 720i, but both are just called HD.
And don't get me started on SD (Standard definition) being anything between 480i and 576p, therefore not being properly standardized at all.
anyway, rant over.