How can PHP developers ensure that form submissions work as intended without interference from nested forms?

PHP developers can prevent interference from nested forms by ensuring that each form has a unique identifier. This can be achieved by adding a hidden input field with a unique name and value to each form. This way, when the form is submitted, PHP can check for the presence of this identifier to ensure that the submission is coming from the intended form.

<form method="post" action="process_form.php">
    <input type="hidden" name="form_id" value="form1">
    <!-- other form fields here -->
</form>

<form method="post" action="process_form.php">
    <input type="hidden" name="form_id" value="form2">
    <!-- other form fields here -->
</form>