The standard error response format in SOAP web services.
A SOAP Fault contains:
- faultcode: error category (Client, Server, VersionMismatch, MustUnderstand)
- faultstring: human-readable message (often generic)
- faultactor: who caused the fault
- detail: carrier-specific structured error data
The detail element is where the useful information lives. It contains carrier error codes, affected field names, and sometimes resolution hints. Always parse detail — never rely solely on faultstring.