Main Landmark
 A main landmark identifies the primary content of the page. 
 ARIA 1.2 Specification: main landmark 
Design Patterns
- Each page should have one mainlandmark.
- The mainlandmark should be a top-level landmark.
- When a page contains nested documentand/orapplicationroles (e.g. typically through the use ofiframeandframeelements), eachdocumentorapplicationrole may have onemainlandmark.
- If a page includes more than one mainlandmark, each should have a unique label.
Use the HTML main element to define a main landmark.
HTML Example: One Main Landmark
When only one main landmark on a page, a label is optional.
                    <main>
                    
                    
<h1>title for main content<h1>
                    
.... main content area ....
                    
</main>
                  <h1>title for main content<h1>
.... main content area ....
</main>
HTML Example: Multiple Main Landmarks
When there is more than one main landmark on a page, each should have a unique label.
                    <main  aria-labelledby="title1">
                    
                    
<h1 id="title1">title for main content area 1<h1>
                    
.... main content area 1 ....
                    
</main>
                    
....
                    
<main aria-labelledby="title2">
                    
<h1 id="title2">title for main content area 2<h1>
                    
.... main content area 2 ....
                    
</main>
                    
                  
                <h1 id="title1">title for main content area 1<h1>
.... main content area 1 ....
</main>
....
<main aria-labelledby="title2">
<h1 id="title2">title for main content area 2<h1>
.... main content area 2 ....
</main>
A role="main" attribute is used to define a main landmark.
ARIA Example: One Main Landmark
When only one main landmark exists on a page, a label is optional.
                    <div role="main">
                    
                    
<h1>title for main content<h1>
                    
.... main content area ....
                    
</div>
                  <h1>title for main content<h1>
.... main content area ....
</div>
ARIA Example: Multiple Main Landmarks
When there is more than one main landmark on a page, each should have a unique label.
                    <div role="main"  aria-labelledby="title1">
                    
                    
<h1 id="title1">title for main content area 1<h1>
                    
.... main content area 1 ....
                    
</div>
                    
....
                    
<div role="main" aria-labelledby="title2">
                    
<h1 id="title2">title for main content area 2<h1>
                    
.... main content area 2 ....
                    
</div>
                    
                  
                <h1 id="title1">title for main content area 1<h1>
.... main content area 1 ....
</div>
....
<div role="main" aria-labelledby="title2">
<h1 id="title2">title for main content area 2<h1>
.... main content area 2 ....
</div>
