102 Processing
Still working on it, said the WebDAV server — a deprecated code.
RFC 2518, the WebDAV of 1999, created 102 so that long operations — a whole-tree MOVE, say — could signal that the server had not died, it was just working, so the client would not hit its timeout.
RFC 4918, the 2007 WebDAV revision, removed it for lack of implementation. The IANA registry still lists it, pointing at the obsolete document; no browser does anything with it. It is a stuffed specimen in the strict sense.
> MOVE /acervo/ HTTP/1.1
> Destination: /reserva/
< HTTP/1.1 102 Processing