Use the appropriate landmarks to identify the different regions of content on a web page.
The most important landmark roles are main and navigation, as nearly every page will include at least those regions.
Other commonly used landmark roles include banner, contentinfo, complementary and search.
Use HTML5 sectioning elements that have a default ARIA landmark role: main (main), nav (navigation), aside (complementary) and in some situations header (banner) and footer (contentinfo). When using these elements, the role attribute should NOT be defined.
In HTML4 and XHTML 1.0 documents, a landmark can be created using a div element with a role attribute and the appropriate ARIA landmark role value (e.g., role="main").
The search role is typically placed on a form element or a div that surrounds the search form.
When there are multiple instances of a particular landmark role on a page, provide a unique accessible name for each landmark with the same role to enable users to differentiate among them.
An alternative landmark can be created in HTML5 by using the section element, which has a default landmark role of region, with an author-defined accessible name (e.g., using aria-labelledby to reference a heading element).
Do not nest landmarks with the same role (e.g., do not place navigation landmarks within a navigation landmark). Instead, use the section element technique described above to provide additional subsections within a standard landmark.
If a region on a page does not correspond to one of the defined ARIA landmark roles, the section element technique described above can be used to create a landmark container for the content.
View the accessible names of the landmarks on the page and verify that each uniquely describes the type of content the landmark contains.
Information about the element associated with the result.
The information typically includes the tag name, accessible name or other information related to the rule requirements.
"Page" means that the result applied to the page. For example, the rule "One main landmark on the page" is a page level rule.
The element position is based on the DOM order of elements in the page.
The element position maybe useful in helping to locate a specific element on the page evaluated (e.g smaller numbers are typically toward the beginning of a page and larger numbers typically toward the end of a page).
Element position 1 is the first element.
The highest element position is the last element.
Element position values for most rule/page results will not be consecutive since a rule only applies to a sub set of elements found on a page.