Essentials for Accessible Documents
Overview
The basics of web accessibility apply to documents, regardless of the application. Though the implementation will vary from application to application, the principles are the same.
Title
The document should begin with its title and needs to be formatted using the Heading 1 style. This should be the only H1 in the document.
Also make sure that you copy the title to the Title field of the document properties. Search engines will display this title, and it will help users find the document.
Semantic Structure
The content of the document should follow a clear structure, utilizing the formatting options for their respective purpose. Headings are the primary way to define the structure of the document. The tags associated with these elements inform the screen reader of content type so that the content can be read back to the user appropriately (e.g. heading, paragraph, list, image, table).
Headings
Use the Heading styles 2 through 6 to define the structure (outline) of your content. Heading styles can be modified as needed in many applications. Using the heading styles will also make it easy to quickly generate a Table of Contents.
Paragraphs
Paragraphs are the basic content blocks of your document. Avoid using empty paragraphs wherever possible. Adjust the heading and paragraph styles to include space before and after to separate the elements.
Lists
Use the list styles based on their purpose. Use the number or letter style (ordered) when the order of the listed items is essential to the meaning (like the steps to a process). When the order is not important and the items are “unordered”, use the bullet style.
Links
The text used for hyperlinks should always be descriptive, giving the reader a clear idea of what to expect when following the link. You should never use “click here” or “read more” for hyperlinks.
Images
Images that contain text must include that text as ALT text. Please note that there is a 140-character limit for ALT text that is read back via screen readers
Images that are decorative and don’t really contribute to the meaning of the content can be marked as “decorative” by selecting the checkb
Note: To make sure a good reading order is maintained, images should be placed inline. Using the advanced positioning functions will separate the image from its text context.
Tables
Tables should be limited to situations in which you need to present data by rows and columns; they should not be used for layout purposes. When a table is included, it should include a header row that defines the data in the columns. Avoid using complex tables with merged cells and multiple headers. The reading order of a table is critical to understanding the data, and complex tables are next to impossible to understand for those using assistive technology.
When the document contains multiple tables, a caption for each is recommended
| Apple Type | Created | Taste |
|---|---|---|
| Gala | 1930s | Sweet and easy eating |
| Granny Smith | 1860s | Incredibly tart, high acid, and subtle sweetness |
| Honeycrisp | 1960s | Juicy, sweet, and crunchy |
Color Contrast
Follow the WCAG guidelines for color contrast between foreground and background colors. The contrast ratio for standard text is 4.5:1, which large text can be 3.2:1. See Color Contrast Requirements for more about the ratios, text sizes, and text with images.
Since blue is often used for a link color, limit its use.
Table of Contents
Including a table of contents is a great feature for documents of some length. When heading styles are used consistently, a TOC can be generated easily.
Creating PDFs
Use the appropriate export or save function of the application that will maintain all the meta data and tagging needed for an interactive PDF.
Reading Order
Applications such as word processing programs keep the content in a consecutive order which is then read back to a user in the proper order when a screen reader is used.
Applications that allow for individual objects or content blocks (e.g., InDesign, PowerPoint) may have a different reading order based on the sequence in which they were added. Use the ordering mechanism of the application to arrange all the content objects in the correct reading order.
Adobe Acrobat Tools
If the final format of your document is a PDF, Adobe Acrobat provides tools to further test and improve the accessibility of your document. However, it is recommended that any needed tweaks be made in the original document and a new PDF generated.