PayPal Notifications. Why are there so many and what's the difference?

everything is called new

[ngentot]

First, they have this variable called "rm". The manual says:

-----
If set to “2” and if return is set, the buyer will be sent back to the return URL using a POST method, to which all available transaction variables will also be posted.
------

And then, there's the IPN.

Now I see they have this "new" thing called Payment Data Transfer.

What are all these? What's the difference from each other? They all seem doing the same thing to me. Even if there's a minor difference, should they just be put together and called one name?

And, what is this New Auto Return thing? I thought you could always set it on your HTML. This is an old feature. But this Auto Return thing is promoted as "New!". So what's the difference?

And what's up with that New(!) Custom Payment pages? You can only customize the background color and put a header logo in an awkward position. I don't really see what's new with that. And calling it "custom" is a strech.

I'm so confused. Maybe soon they will have an ad that says "NEW! Receive payment online!"

[PayPalPB]

rm=2 causes the payment details to be POSTed to the "return" URL.

IPN POSTs the payment details to a URL you specify either in your Profile or in "notify_url". IPNs are more reliable since they retry until successful and do not rely on the user pressing Continue.

Auto-Return is new as of February. PDT is to be used only with Auto-Return and works differently from IPN.

Custom Pages are also new as of February.