WCAG 2.2 Guideline 1.1 Text Alternatives:
Provide text alternatives for any non-text content so that it can be changed into other forms people need, such as large print, braille, speech, symbols or simpler language.
WCAG 2.2 Success Criterion 1.1.1 Non-Text Content:
All non-text content that is presented to the user has a text alternative that serves the equivalent purpose, except for certain situations.
Controls, Input
If non-text content is a control or accepts user input, then it has a name that describes it's purpose.
Time-Based Media
If non-text content is time-based media, then text alternatives at least provide descriptive identification of the non-text content. (See related topics for more information on Time-Based Media)
Test
If non-text content is a test or exercise that would be invalid if presented in text, then text alternatives at least provide descriptive identification of the non-text content.
CAPTCHA
If the purpose of non-text content is to confirm that content is being accessed by a person rather than a computer, then text alternatives that identify and describe the purpose of the non-text content are provided, and alternative forms of CAPTCHA using output modes for different types of sensory perception are provided to accommodate different disabilities.
Decoration, Formatting, Invisible
If non-text content is pure decoration, is used only for visual formatting, or is not presented to users, then it is implemented in a way that it can be ignored by assistive technology.