wp-includes/feed.php:451Displays the HTML type based on the blog setting.
function html_type_rss() { $type = get_bloginfo( 'html_type' ); if ( str_contains( $type, 'xhtml' ) ) { $type = 'xhtml'; } else { $type = 'html'; } echo $type;}Introduced in 2.2.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/feed.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.