SOAPENC

SOAPENC refers to the set of encoding rules used with the SOAP protocol, specifically the SOAP Encoding defined for SOAP 1.1. It describes how data types are serialized into XML within a SOAP message when using the RPC/Encoded style. The encoding rules are identified by the SOAP-ENC namespace and provide mechanisms for representing primitive types, structures, and arrays, including how type information is conveyed and how complex object graphs can be referenced within a message.

Historically, SOAP Encoding emerged as part of the early SOAP 1.1 specifications to support remote procedure calls in a platform-agnostic way. It allowed clients and servers to communicate using a typed, hierarchical representation of data and to serialize complex objects into a single SOAP envelope. This encoding style enabled features such as multi-reference graphs and explicit array typings, which were useful for certain RPC scenarios.

Over time, SOAP Encoding gained scrutiny for interoperability and extensibility concerns. Many web services adopted the Document/Literal style instead, which separates the data model from the encoding rules and tends to be more predictable across diverse platforms. In practice, RPC/Encoded (SOAP Encoding) is less commonly used in new services, and various standards and profiles, including the WS-I Basic Profile, discourage or restrict its use in favor of literal encoding.

Today, SOAP Encoding remains relevant mainly for legacy systems and in contexts where existing clients and servers rely on encoded SOAP messages. Modern SOAP implementations and tooling often emphasize document/literal approaches, but understanding SOAPENC is still useful for historical context and for maintaining older integrations.