On 05/03/2012 01:46 AM, Wladimir wrote:

Label is a label for the destination address, message is a freeform message describing the transaction.

I don't think the message is currently stored in the Satoshi client. That feature is somewhere on our way-too-long issue and todo list.

But I understand that you want to add transaction meta-data fields such as contact information, bought items, item prices?

I don't want to add fields to the URI-spec, I just want to add them to the client. To me, it is ideal to have separate strings for labeling addresses vs labeling transactions -- i.e. different strings would show up in the address book (owner info) than what shows up in the transaction history (purchase info). I say it's ideal because that concept seems to fit perfectly with availability of "label=" and "message=" fields in BIP 21, but it won't actually work if Bitcoin-Qt won't/can't do it that way.

For now, it seems that I should count on all important information being in the label field, since users creating URLs would have to assume anything in the message field will not be saved. Though I imagine the message data will be displayed after the URI is clicked, just not saved.

To expand the concept slightly further, it might make sense in the future for users to populate the message and label fields with lots of data, using newlines. The first line would be used as a summary and displayed in the address book and ledger. The extra lines would all be displayed when the user opens up a details window. All of it would be automatically generated by the merchant, and the purchaser would end up with detailed documentation on every purchase they've made for zero effort.

-Alan