As many of us are concerned about Tax and VAT it would really help us to get a document that clearly specified that we did not buy a Librem 5 but that we BACKED its crowfunding project instead of a getting a “classical” invoices. Or, at least, mentioned it clearly on the invoice.
As you probably know, regulators outside the US are quite painful sometime… actualy, inside the US too and all the time 
So, to ease/prevent situations like:
“The parcel is blocked by the customs and they ask me to prove that I didn’t purchase a product but instead, that I did participate in a crowdfunding to support the development of a project and that the device is a reward from my donation/contribution.”
It is good to know that according to the EU regulations (that I am currently aware of) there is no tax to pay on a reward (only the reward not the delivrery cost!!) that you get from a crowdfunding project that you’ve backed.
I was confronted to this situation when my Pine64 arrived at the customs here in Belgium.
They asked me to declare and pay the importation taxes + the VAT for it or they will simply destroy it…
Fortunatly for me, I was able to prove that the Pine64 was a reward so I didn’t have to pay these taxes.
BUT, as “they” are real pain in the a… I had to pay the VAT on the delivrery cost because it was coming from outside the EU and it didn’t included them… 21% on 10$ (on wich I had to apply the right daily $/€ conversion of my contribution!). When I say they are pain in the…
The good news for the EU backers is, the Librem 5 is sent for free so we don’t have to worry about this 
So, to me, the solution would simply be that Purism makes a document that certified that the content of the parcel is a reward for a contribution in the “Librem 5 crowdfunding project”.
Please, don’t hesitate to tell us here if you have more recent or accurate info on the matter than mine.
In the mean time, I d’ like to congratulate all the backers and, of course, Purism for this successful campain!
WELL DONE! 
A+
Debcool