wp-includes/html-api/class-wp-html-open-elements.php:244Returns whether an element is in a specific scope.
$tag_namestring$termination_liststring[]bool public function has_element_in_specific_scope( string $tag_name, $termination_list ): bool { foreach ( $this->walk_up() as $node ) { $namespaced_name = 'html' === $node->namespace ? $node->node_name : "{$node->namespace} {$node->node_name}"; if ( $namespaced_name === $tag_name ) { return true; } if ( '(internal: H1 through H6 - do not use)' === $tag_name && in_array( $namespaced_name, array( 'H1', 'H2', 'H3', 'H4', 'H5', 'H6' ), true ) ) { return true; } if ( in_array( $namespaced_name, $termination_list, true ) ) { return false; } } return false; }Introduced in 6.4.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/html-api/class-wp-html-open-elements.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.