Comprehensive web accessibility is a standard at IU, not just a goal. An accessible website can be independently perceived, understood, navigated, and operated by as many individuals as possible, regardless of any disabilities: cognitive, hearing, sight, mobility, etc.
Assistive Technologies like screen readers, braille pads, etc. rely on semantic HTML markup. Think of this as you’re trying to communicate function (purpose) over form (looks). For example, HTML standards discourage use of the element i (italic), in preference of more accurate elements such as em (emphasis). This is because italics are used for purposes other than emphasis, such as citing a source, foreign phrases or loanwords.