Re: [Taler] caps are about currency not coins

[Sebastian Javier Marchano]

Hi Fabian, 

So as taler coins can reflect any currency on earth, i suggest to run a
bank which has "$18+", "$21+" as well as "$" in their currency
portfolio. And then any service may say "please id, or use $21+ coins".
The bank knows their customers but not their spending behaviour.
Europeans may choose "€", "€16+", "€18+".

one attribute you want the system to have is that the user of the GNU Taler reveals no information about it's condition when spending the coins. 

So in your case, having different currencies (EUR+16, EUR+18, EUR) will make the information about the user age available to merchants.

The goal of Ozgur's proposal is to achieve the same behavior and the receiver of the coins should only know if you have enough money or not.

My guess (because I haven't see the details :) ) is that if the user have coins just for under-18-products and the contract terms says that you are buying restricted products (like beer) when the merchant tries to deposit the coins using the /coins/$COIN_PUB/deposit endpoint the exchange will end with some of the error codes.

Best regards

--
Sebastian

On Mon, 6 Sept 2021 at 04:19, Fabian Kirsch <fabian.kirsch@posteo.de> wrote:

Hi

The whole capabilities feature is a currency feature. And therefor
outside of talers implementation concern.

So as taler coins can reflect any currency on earth, i suggest to run a
bank which has "$18+", "$21+" as well as "$" in their currency
portfolio. And then any service may say "please id, or use $21+ coins".
The bank knows their customers but not their spending behaviour.
Europeans may choose "€", "€16+", "€18+".

For other caps like "$,food only" it is the bank that checks its
merchants to be eligible. The service could advertise "we accept
$-food-only". This allows questions like "does beer count as food" to be
settled different in different parts of the world.


This also makes the whole topic a regional one, where cultural norms are
more likely to find agreement whether they want the capabilty feature or
not.

greetings Fabian