Are there any best practices for handling cookie data across multiple domains in PHP?

When handling cookie data across multiple domains in PHP, it is important to set the cookie domain parameter to the root domain so that the cookie can be accessed by all subdomains. This can be done by setting the domain parameter in the setcookie function to ".yourdomain.com". Additionally, make sure to set the cookie path parameter to "/" to ensure the cookie is accessible across all directories within the domain.

setcookie('cookie_name', 'cookie_value', time() + 3600, '/', '.yourdomain.com');