SOX is a payment protocol that is implemented within WebFunds as a wallet. It consists of a request model over an encryption layer. Requests go from client to server, and replies back from the server to the client.
Requests have these characteristics:
Documentation is a little scattered. Here's some from the various Systemics' sources:
Start with the Executive Summary, above. Here are some other terms not covered there.
account is primarily a public and private key pair created by the SOX Client. The private key is kept secret and the public key can be registered with the SOX Server, thus making the account the unit of authentication.
item is a SOX value identifier (byte array), literally, the field in the SOX payment or the SOX sub account that identifies value type. As far as the SOX protocol is concerned, this can be anything; as far as the current implementations goes, it is the identifier for a Ricardian contract.
subaccount is the unit of work. In general, with a standard payments implementation, this consists of the item, and a database containing any receipts collected, and state of any pending transactions.