||IndieUI: User Context defines a set of preferences that users can choose to expose
to web applications, and an API for user agents to access the preferences and listen
for changes. User can set preferences for features such as screen and font size, color,
and typographical preferences. Users with disabilities can provide information about
assistive technologies in use, indicate that the display is in an accessibility mode,
and indicate whether and what kind of subtitles and audio descriptions they need.
Web applications can use this information to optimize the presentation without a requirement
to target a specific device, operating system, or locale. While customizations based
on these properties benefit users, the information could also be used to make assumptions
about users or compromise anonymity. Therefore, the specification includes user agent
requirements to allow users to opt out and choose not to expose information on a category
basis to preserve privacy.