wp-includes/deprecated.php:1597Retrieve the specified author's preferred display name.
$auth_idintoptionalfalsestringfunction get_author_name( $auth_id = false ) { _deprecated_function( __FUNCTION__, '2.8.0', 'get_the_author_meta(\'display_name\')' ); return get_the_author_meta('display_name', $auth_id);}Introduced in 1.0.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/deprecated.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.