The ISO/IEC 20944 series of International Standards provides the bindings and their interoperability for metadata registries, such as those specified in the ISO/IEC 11179 series of International Standards. ISO/IEC 20944-4:2013 contains provisions that are common to protocol bindings and the protocol bindings themselves. The protocol bindings have commonality in their conceptualization of the services provided. Common features include:

• common data transfer semantics;
• harmonized session services for connection-oriented and connection-less protocols.

Bindings for HTTP and WebDAV protocols are provided.