wp-includes/general-template.php:1009Displays the Site Icon URL.
$sizeintoptional512$urlstringoptional''$blog_idintoptional0function site_icon_url( $size = 512, $url = '', $blog_id = 0 ) { echo esc_url( get_site_icon_url( $size, $url, $blog_id ) );}Introduced in 4.3.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/general-template.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.