Strength of Evidence:
Document Type: Guideline
Do not assume that all users will have the same browser features, and will have set the same defaults.
Users with visual impairments tend to select larger fonts, and some users may turn off backgrounds, use fewer colors, or overrides font. The designer should find out what settings most users are using, and specify on the Web site exactly what assumptions were made about the browser settings.
Related Usability Guidelines: