PM receipt question

Ive always wondered about this: if you send a pm with a receipt request, when does it generate an "unconfirmed" receipt? Is it when the recipient sees the PM but decides not to send a receipt? Basically, if I see a that a PM has an unconfirmed receipt, can I assume that the recipient has seen that they have a message from me, but chose not to read it or respond?

Thanks!

The unread receipt is generated as soon as your PM is sent, whether it is seen or not. If the recipient does not acknowledge receiving the PM there's no way to tell if it's been read. They can read it and choose not to click the receipt button or ignore it and not read it at all. The only way to know is if they actually click the receipt button.