Most popular variants of the header value (we only show this when there's just a bunch of variants):

Client Hints is a new proposed header that requests additional user agent information such as device pixel ratio (DPR), screen width etc. The header standardizes the way this information is delivered from the client browser through a HTTP header, rather than previously employed JavaScript APIs.

Reference...

We have seen 38 websites setting the Accept-CH HTTP header and 18 unique values of this header.