Aloha Tatiana! I wish your questions had straightforward easy answers – and if you are government funded it kind of is. (See here: https://www.ada.gov/websites2_prnt.pdf) if you are not government funded, this is something that is currently being debated in the legal system. That being said, the WCAG 2.0 guidelines are a good set of guidelines to help protect yourself if you feel you should. (You can see more on WCAG here: https://www.yokoco.com/find-out-how-to-make-your-website-compliant/)
The U.S. Department of Health and Human Services (HHS) also enforces Title II of the ADA relating to access to programs, services and activities receiving HHS federal financial assistance. This includes ensuring that people who are deaf or hard-of-hearing have access to sign language interpreters and other auxiliary aids in hospitals and clinics when needed for effective communication.
“Any business that is considered a “place of public accommodation” is required to provide equal access to services under the nondiscrimination requirements of Title III of ADA. When you look at the guidelines closely, this includes hotels, entertainment venues, legal and accounting firms, retail stores, and virtually every business that is not a private club, including businesses that exist solely on the web.” (Read full article.)
You may have installed a ramp, increased the width of your door frames, or made other accommodations to ensure that your physical premises are accessible to all. The requirement for equal access used to only apply to physical locations and storefronts, but now the government is actively ensuring that the requirements for ADA accessibility include online properties such as websites and mobile apps.
The words in the tag should be more than a description. They should provide a text equivalent of the image. In other words, the tag should include the same meaningful information that other users obtain by looking at the image. In the example of the mayor’s picture, adding an “alt” tag with the words “Photograph of Mayor Jane Smith” provides a meaningful description.