For Mac OS users, there is a system setting that may not allow you to tab onto several types of elements in a web page. To change this setting:
The Americans with Disabilities Act requires employers to provide “reasonable accommodations” to employees with a disability, physical or mental impairment that limits one or more major life activities.
Need accommodations?
The first step in requesting a reasonable workplace accommodation is:
ADA Resources:
The Americans with Disabilities Act Questions and Answers
EEOC Disability-Related Resources