ICD-001 is a network communication protocol based on XML. The protocol is used over standard TCP/IP client-server connections.
There are two documents that describe the protocol in detail. The primary document, RND-S0053, covers the protocol, including message structure, message framing and all the outgoing messages. The second document, RND-S0058, covers all the commands, these are the incoming message, in other words control messages that an external application or system can send to Witness.