What are some common pitfalls to avoid when using htmlentities() in PHP for form data?

One common pitfall to avoid when using htmlentities() in PHP for form data is not specifying the correct character encoding. This can result in special characters not being properly encoded, leading to potential security vulnerabilities such as cross-site scripting (XSS) attacks. To solve this issue, always specify the correct character encoding (e.g., UTF-8) when using htmlentities() to ensure that all special characters are properly encoded.

// Specify the correct character encoding (e.g., UTF-8) when using htmlentities()
$form_data = htmlentities($_POST['form_data'], ENT_QUOTES, 'UTF-8');