wp-includes/html-api/class-wp-html-processor.php:6488Returns whether a given element is an HTML Void Element
$tag_namestringbool public static function is_void( $tag_name ): bool { $tag_name = strtoupper( $tag_name ); return ( 'AREA' === $tag_name || 'BASE' === $tag_name || 'BASEFONT' === $tag_name || // Obsolete but still treated as void. 'BGSOUND' === $tag_name || // Obsolete but still treated as void. 'BR' === $tag_name || 'COL' === $tag_name || 'EMBED' === $tag_name || 'FRAME' === $tag_name || 'HR' === $tag_name || 'IMG' === $tag_name || 'INPUT' === $tag_name || 'KEYGEN' === $tag_name || // Obsolete but still treated as void. 'LINK' === $tag_name || 'META' === $tag_name || 'PARAM' === $tag_name || // Obsolete but still treated as void. 'SOURCE' === $tag_name || 'TRACK' === $tag_name || 'WBR' === $tag_name ); }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-processor.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.