It is important that related list items be structured as a list to allow AT users to efficiently navigate the content. List structures help assistive technology users to identify and understand the relationship items have to each other.
Only symbols that are commonly recognized as list bullets should precede list descriptions. Inappropriate symbols may confuse assistive technology users when determining list content. For example, smiley faces or the registered symbol are not meaningful as bullet identifiers. If it is not possible to use a meaningful symbol, authors need to apply custom text to the symbol in the alternate text field of the symbol’s parent tag.
Structure of Lists
Think of the structure of lists and list items as a family tree. There are the parents, which are the main list items. Then there are the children, or sub-lists, under one parent item. All list items contained at the same level can be thought of as siblings. In Adobe Acrobat, each list structure must consist of a parent <L> tag and subsequent list item <LI> tags for each item in the list. If there are total of eight fruits listed, then there needs to be eight <LI> tags in the structure. Each list item <LI> tag must contain a label <lbl> tag that includes the number or bullet and a list item body <LBody> tag that contains the text of the item. Below is an example of proper list structure:
Example List Structure:
A sub-list must be structurally under, as a child, the list item to which it is related. It is placed after the text of the parent list item. Below is an example of a sub-list structure:
- Granny Smith
- Sour Apple
Example sub-list structure:
Pay attention to lists that span across multiple pages. Even though a list continues on to another page, it is important that in the tag structure those list items are part of the original list and not a list of their own. Attention to detail of these items enables users to associate related content and know the total number of related items.