banner constant
A region that contains mostly site-oriented content, rather than page-specific content.
Site-oriented content typically includes things such as the logo or identity of the site sponsor, and site-specific search tool. A banner usually appears at the top of the page and typically spans the full width.
User agents SHOULD treat elements with the role of banner as navigational landmarks.
Within any document or application, the author SHOULD mark no more than one element with the banner role.
Note: Because document and application elements can be nested in the DOM, they may have multiple banner elements as DOM descendants, assuming each of those is associated with different document nodes, either by a DOM nesting (e.g., document within document) or by use of the aria-owns attribute.
See: developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/Roles/banner_role
Implementation
static const String banner = 'banner';