How can special characters like +, &, = be passed through a form in PHP without being modified?

Special characters like +, &, = can be passed through a form in PHP without being modified by using the urlencode function to encode the special characters before sending them through the form. This ensures that the special characters are preserved and can be decoded on the receiving end.

// Encode special characters before sending through the form
$encoded_value = urlencode($value);

// Decode the encoded value on the receiving end
$decoded_value = urldecode($encoded_value);