Links
Use clear and accurate link text, by using phrases that are to the point and make sense on their own or as part of a list of links (i.e. link descriptions should say more than just "click here").
Do not user URL shorteners (bit.ly, etc.); they should only be used for social media purposes.
Do not use the same link description more than once on a page when the links point to different URLs.
Writing style
Use of a clear writing style is helpful for everyone especially those with cognitive disabilities. Elements of a clear writing style include:
- Headings are clear, accurate and informative so users can scan the content without having to read through the entire paragraph or page.
- The paragraph topic is at the beginning.
- There is one idea per paragraph.
- Abbreviations or acronyms are spelled out in full the first time they are used.
- Commonly used words are used (e.g. no slang or jargon).
- Sentences are simple.
PDF files
Don't use a PDF file unless an HTML file can't provide your website visitor with the information or functionality required.
PDF files do not contain the underlying structural tags such as headings or alternative text that are required for accessibility (without effort from the author).
If you must use a PDF file, try to ensure that it's accessible. Check out WebAIM for instructions on converting documents to PDF.
Images
Avoid using any unnecessary images.
Avoid using images of text, graphical buttons or other images; unless you make them accessible with text equivalents (describe the function of the image). However whenever possible, use actual text instead of images of text with an alt-tag. Text magnifies better than images, making it more accessible for people with low vision.
For a detailed image (e.g. a chart), describe the image on the page where everyone can read it.
If an image provides no additional information or serves no real purpose on your page other than decoration, allow assistive technology to ignore it by using an empty alt tag (alt="") in the Source editor.
Colour contrast
Make sure that foreground colours are sufficiently differentiated from background and/or adjacent colours. Even where sufficient contrast may seem evident, it may still be a problem for those who are colour blind (e.g. red text on green background).
In addition to colour contrast, elements should be understandable and comparable without relying on colour alone.
Example: avoid statements such as “click on the green button” or links in body text that are only coloured (i.e. not underlined), making them difficult to distinguish from the body text.
Frames
As a general guideline, avoid using frames.
For users using a screen reader it can add levels of complexity.
Multimedia and other file formats
Use captions and, if possible, a transcript or some other alternative for audio and video.
Dynamic content and scripting
If scripts, applets, or plug-ins are used to implement content ensure that equivalent content is provided which does not require scripts, applets or plug-ins, and that the content is kept up to date.
If you are using dynamically changing elements on a Web page, provide a way for users to pause or stop them. Avoid flickering or blinking effects such as quick motion or sudden changes in color. These effects may induce seizures.
If your dynamic content or script uses a mouse for interaction, ensure that the keyboard can be used as well.