In what situations should PHP developers be cautious about using HTML tags in database entries and how can they ensure proper formatting while avoiding security risks?

PHP developers should be cautious about using HTML tags in database entries when displaying user-generated content on a website, as this can lead to security vulnerabilities such as cross-site scripting (XSS) attacks. To ensure proper formatting while avoiding security risks, developers can use PHP functions like htmlspecialchars() to escape special characters in the input data before storing it in the database.

// Example of using htmlspecialchars() to escape special characters before storing data in the database
$user_input = "<script>alert('XSS attack');</script>";
$escaped_input = htmlspecialchars($user_input);
// Store $escaped_input in the database