wp-includes/deprecated.php:2464Callback used to change %uXXXX to &#YYY; syntax
$matchesarraystringfunction funky_javascript_callback($matches) { return "&#".base_convert($matches[1],16,10).";";}Introduced in 2.8.0. 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.