What are the potential pitfalls of using deprecated PHP functions like $REMOTE_ADDR instead of $_SERVER['REMOTE_ADDR']?

Using deprecated PHP functions like $REMOTE_ADDR instead of $_SERVER['REMOTE_ADDR'] can lead to compatibility issues with newer PHP versions and may result in security vulnerabilities. It is important to update your code to use the correct, updated superglobal variables like $_SERVER['REMOTE_ADDR'] to ensure your application remains secure and functional.

// Correct way to get the remote IP address
$remote_ip = $_SERVER['REMOTE_ADDR'];