Accessibility
Accessibility is the design of products, services, [...] or environments so as to be usable by people with disabilities. The concept of accessible design and practice of accessible development ensures both "direct access" (i.e. unassisted) and "indirect access" meaning compatibility with a person's assistive technology (computer screen readers, keyboard only access).
As an editor, it is your responsibility to help provide accessible content.
Writing accessible text
See also the following W3C page: Writing for Web Accessibility
Provide informative, unique page titles
The title of a page can - in most cases - be influenced in the page properties. Part of the page title - such as the name of the organization - might be added automatically. Ask your developer about this.
Use headings to convey meaning and structure
Almost all content elements have the ability to provide a heading.
Depending on your user rights you may also be able to influence the level of the heading (Headlines > Type). The choice of the level of the heading should be made in accordance to the semantics of the text and not according to design choices.
The rich text editor (RTE) also offers the ability to create headlines of different levels.
Make link text meaningful
When creating links in the RTE write the meaningful link text, highlight it and then click the link button.
If you are linking an image the image should have a meaningful alternative text.
It is also possible to link headlines of content elements. In this case the text of the headline itself becomes the link text.
Write meaningful text alternatives for images
See also
Writing alternative text can prove difficult. Here is a helpful guide: https://axesslab.com/alt-texts/ .
In TYPO3 when you are uploading or managing an image file in the module File > Filelist you can provide an alternative text in the metadata of this file.
When you are displaying an image as Image content element you can override the alternative text to fit the context or use the default.
Note
An alternative image text is usually not visible. However, the description of an image is usually displayed below the image. Therefore the alternative text needs to supply the information supplied by the image to most users. The description text should supply additional information to all users.