Google Play order id uniqueness

Question

Currently, Google Play order IDs have this format: GPA.XXXX-XXXX-XXXX-XXXXX Previously, they was like: {merchant_id}.{order_id_number} - and it was pretty unique across all merchant accounts.

But, now, i have doubts about uniqueness of order IDs in that new 'GPA...' format. Here i speaking exactly about GLOBAL uniqueness (across all accounts), but not about uniqueness across one specific account.

So, are they globally unique or not? I couldn't found information about that...

Thank you!