Labelledby for Main

I want to come with you to Alderaan. There's nothing for me here now. I want to learn the ways of the Force and be a Jedi, like my father before me. Remember, a Jedi can feel the Force flowing through him.

ARIA Landmarks are roles that create navigable regions of the page:

banner is supposed to contain site-oriented content rather than page-specific content. There should be only one banner landmark on a page. The HTML5 <header> element inherits the banner role, when used at top level.
complementary is supposed to be a supporting region of the document, designed to be complementary to the main content at a similar level in the DOM hierarchy, but which remains meaningful when separated from the main content. The HTML5 <aside> element inherits the complementary role. Some DOM implementations will only give <aside> the complementary role, when not at top level, if the element has an accessible name.
contentinfo is supposed to be a region of the page containing information about the parent document, such as copyright or privacy information. There should be only one contentinfo landmark on a page. The HTML5 <footer> element inherits the contentinfo role, when used at top level.
form is supposed to contain elements or objects that combine to create a form. It is only a navigable landmark if it has an accessible name.
main is supposed to contain the main content of the document. There should be only one main landmark on a page. The HTML5 <main> element inherits the main role.
navigation is supposed to contain elements used for navigating the document or related documents. The HTML5 <nav> elements inherits the navigation role.
region is supposed to contain content that is relevant to a specific, author-specified purpose and sufficiently important that users will likely want to be able to navigate to the section easily and to have it listed in a summary of the page. The HTML5 <section> element inherits the region role, if the element is given an accessible name.
search is supposed to contain elements or objects that combine to create a search facility.

<footer> and <header> elements nested within other sectioning elements, such as <section> or <article>, should not inherit landmark roles.

First Heading in the Article (Article Should Not Be a Landmark)

Header Heading Nested in the Article (Nested Header Should Not Be a Landmark)

Labelledby for First Section (Is Region Landmark if Section is Named)

Hokey religions and ancient weapons are no match for a good blaster at your side, kid.

Labelledby for Second Section (Is Region Landmark if Section is Named)

Don't act so surprised, Your Highness. You weren't on any mercy mission this time. Several transmissions were beamed to this ship by Rebel spies. I want to know what happened to the plans they sent you. She must have hidden the plans in the escape pod. Send a detachment down to retrieve them, and see to it personally, Commander. There'll be no one to stop us this time!

Heading for Div with Role Equal Nothing

What's wrong? I felt a great disturbance in the Force...as if millions of voices suddenly cried out in terror and were suddenly silenced. I fear something terrible has happened.