monge
I can only speak for what happens in Portugal.
Portugal is a member of the European Union (EU) and has the sovereign right to mint coins in its territory.
Each issued coin is based on a Decree-Law and this decree expressly states:
1 - The reason why the coin is issued.
2 -Description of the coin, such as values, symbols, metals, weight and diameter, etc.
3 - Quantities of each minted value.
In addition, it cleary establishes that no one can refuse to receive such a coin and, for large-value payments, the maximum number of coins that each person or institution is obliged to receive.
Therefore, these coins are Commemorative Circulation Coins.
In addition, the same Decree establishes how many of these coins can be issued in noble metals or with special finishes, such as Brilliant Uncirculated (BNC) and Proof. These are coins intended for collectors and are classified as Non-Circulating Commemoratives Coins.
If I was a lawyer, I could certainly provide a better basis for what I have just written.
Thanks for the answer. On the other hand, all these decree-laws also point to the earlier one from 2007, which says in the article 3, paragraph 1: “Collector's coins are issued for numismatic purposes and are not intended to satisfy the necessities of monetary circulation” (unlike commemorative versions of circulating coins in the separate article).
Decreto-Lei n.º 246/2007 | DR
I'm not a lawyer either, but this seems to fit perfectly with the Numista definition of non-circulating coins quoted by tdziemia. You're right that there is the legal obligation to accept them, but it also includes the proof version, which is obviously non-circulating (the decree-law for every such coin establishes the legal tender status for “coins struck within the frame of the present document,” not specifying if it means only BU coins or not). Furthermore, the legal tender status rather means that the collector's coin is not a private medal and can be theoretically used for payments in my opinion.
I don't pretend to know Portuguese coins and coinage laws better than you do, but even with my limited knowledge of Portuguese, these laws seem to confirm that the BU collector's coins are non-circulating issues (although they are exchanged at FV without any special packaging). At the same time, my humble opinion is that the Numista catalogue should be consistent. If one looks at similar BU Euro coins of other nations (like 5 Euros (Western Capercaillie) - Slovakia – Numista for instance), they are classified as non-circulating in most cases and I strongly suspect that the legislation behind them would be really similar as in the case of Portugal.
I just wanted to express my opinions and arguments on this topic and I suppose it's up to someone from the Numista team in the end to decide how it should be done. So no offence meant if I didn't agree with the way how you see the status of these coins.