wp-includes/deprecated.php:2047Checks and cleans a URL.
$urlstring$protocolsarrayoptionalnull$contextstringoptional'display'stringfunction clean_url( $url, $protocols = null, $context = 'display' ) { if ( $context == 'db' ) _deprecated_function( 'clean_url( $context = \'db\' )', '3.0.0', 'sanitize_url()' ); else _deprecated_function( __FUNCTION__, '3.0.0', 'esc_url()' ); return esc_url( $url, $protocols, $context );}Introduced in 1.2.0. 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.