Identity Token is NOT required for PayPal's Payment Data Transfer (PDT)?

I've setup a PayPal site which uses IPN and I was having trouble getting PayPal to send the GET variables to the return URL that I had specified. It was sending the user's browser to the return URL, but nothing was being passed via GET or POST.

I changed one setting in the PayPal business account: "Payment Data Transfer (optional)" to On which generated an "Identity Token" on the PayPal website.

I also got an automated email from PayPal saying:

    ---------- Forwarded message ----------
    From: service@paypal.com <service@paypal.com>
    Subject: Payment Data Transfer (PDT) Has Been Enabled
    
    This email is to inform you that you have successfully enabled Payment Data Transfer.
    
    PDT's primary function is to display payment transaction details to buyers when they are redirected back to your site upon payment completion. However, there are cases, such as with pending transactions, where you won't receive notification of all transactions. For this reason, PayPal strongly recommends that you also enable Instant Payment Notification (IPN).
    
    To learn more about enabling and setting up IPN:
    https://www.paypal.com/us/cgi-bin/?cmd=p/xcl/rec/ipn-intro-outside
    
    To learn more about Payment Data Transfer, including setup instructions and a complete list of variables:
    https://www.paypal.com/us/cgi-bin/?cmd=p/xcl/rec/pdt-intro-outside
    
    Sincerely,
    PayPal

Clicking on the second link and clicking on "Technical Overview" (https://www.paypal.com/us/cgi-bin/webscr?cmd=p/xcl/rec/pdt-techview-outside) shows:

> Your POST should be sent to
> https://www.paypal.com/cgi-bin/webscr.
> You must post the transaction token
> using the variable "tx" and the value
> of the transaction token previously
> received (e.g.
> "tx=transaction_token"), and the
> special identity token using the
> variable at and the value of your PDT
> identity token (e.g.
> "at=identity_token"). You will also
> need to append a variable named "cmd"
> with the value "_notify-synch", for
> example "cmd=_notify-synch", to the
> POST string.

However, I am NOT passing the Identity Token at all, yet everything is working fine! 

Identity Token is NOT required for PayPal's Payment Data Transfer (PDT)?
===


I've setup a PayPal site which uses IPN and I was having trouble getting PayPal to send the GET variables to the return URL that I had specified. It was sending the user's browser to the return URL, but nothing was being passed via GET or POST.

I changed one setting in the PayPal business account: "Payment Data Transfer (optional)" to On which generated an "Identity Token" on the PayPal website.

I also got an automated email from PayPal saying:

    ---------- Forwarded message ----------
    From: service@paypal.com <service@paypal.com>
    Subject: Payment Data Transfer (PDT) Has Been Enabled
    
    This email is to inform you that you have successfully enabled Payment Data Transfer.
    
    PDT's primary function is to display payment transaction details to buyers when they are redirected back to your site upon payment completion. However, there are cases, such as with pending transactions, where you won't receive notification of all transactions. For this reason, PayPal strongly recommends that you also enable Instant Payment Notification (IPN).
    
    To learn more about enabling and setting up IPN:
    https://www.paypal.com/us/cgi-bin/?cmd=p/xcl/rec/ipn-intro-outside
    
    To learn more about Payment Data Transfer, including setup instructions and a complete list of variables:
    https://www.paypal.com/us/cgi-bin/?cmd=p/xcl/rec/pdt-intro-outside
    
    Sincerely,
    PayPal

Clicking on the second link and clicking on "Technical Overview" (https://www.paypal.com/us/cgi-bin/webscr?cmd=p/xcl/rec/pdt-techview-outside) shows:

> Your POST should be sent to
> https://www.paypal.com/cgi-bin/webscr.
> You must post the transaction token
> using the variable "tx" and the value
> of the transaction token previously
> received (e.g.
> "tx=transaction_token"), and the
> special identity token using the
> variable at and the value of your PDT
> identity token (e.g.
> "at=identity_token"). You will also
> need to append a variable named "cmd"
> with the value "_notify-synch", for
> example "cmd=_notify-synch", to the
> POST string.

However, I am NOT passing the Identity Token at all, yet everything is working fine! 
