Re: [w3ctag/design-reviews] Partial freezing of the User-Agent string (#467)

@ocram 

GREASEing by adding non-existent browser names would avoid blocking of unknown browsers (which as @mcatanzaro indicated, *is* a major problem today). 

One can also imagine sending invalid headers that would also be correctly parsed by valid Structured Headers parsers, to avoid error-prone regex based "parsing". (e.g. `"Chrome"; v="73", "GibberishFirefox 66 dfgdfg"`)

GREASEing by pretending to be other browsers (to avoid their explicit, intentional blocking) would indeed carry compat risk, so would require further experimentation.

It [seems](https://github.com/WICG/ua-client-hints/issues/52#issuecomment-583024730) like WebKit today has a list of websites where their UA strings lie to for their own compat benefit. 
One could imagine a distant future where browsers would keep a similar list on which they perform targeted GREASEing (somewhat similar to what @mcatanzaro [suggested](https://github.com/w3ctag/design-reviews/issues/467#issuecomment-583110469)) in order to dissuade known compatibility offenders from their practices. Enabling GREASEing in the first place seems like a good first step in that direction.

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/w3ctag/design-reviews/issues/467#issuecomment-583704232