208 Already Reported

HTTP 208 Already Reported is used exclusively inside a 207 Multi-Status response body, not as a standalone top-level status, to avoid repeatedly enumerating the same resource multiple times when WebDAV bindings create more than one path to it. WebDAV supports binding, letting a single resource appear at several different URLs within a collection hierarchy, similar to a hard link on a filesystem. When an operation like PROPFIND traverses such a structure and would otherwise report the same underlying resource once for every path that reaches it, 208 lets the server report it fully the first time and then simply note, on later encounters, that it has already been reported.

This keeps multistatus responses compact and unambiguous when a deeply bound collection tree would otherwise produce a combinatorial explosion of duplicate entries for the same underlying resource. Because most WebDAV servers do not implement multiple bindings to the same resource, and most filesystems and object stores expose a strict tree without hard-link-like semantics, 208 is one of the least frequently encountered status codes in real traffic, appearing almost exclusively in WebDAV implementations that specifically support the DAV binding extension.

Client libraries need explicit support for 208 inside a multistatus body to avoid either double-counting a resource or, worse, failing to parse the response at all because an unrecognized inner status confuses a naive parser. Since binding support is optional in WebDAV and rarely deployed, most general-purpose HTTP and WebDAV client code can safely treat 208 as an edge case to handle gracefully rather than something to actively test against in everyday integrations.