Merge pull request #2744 from httpwg/resumable-upload/content-location

Resumable Uploads: Subsequent resources using `Content-Location`

draft-ietf-httpbis-resumable-upload.md

@@ -423,6 +423,10 @@ The `Upload-Complete` header field MUST only be used if support by the resource
 
 The `301 (Moved Permanently)` and `302 (Found)` status codes MUST NOT be used in offset retrieval ({{offset-retrieving}}) and upload cancellation ({{upload-cancellation}}) responses. For other responses, the upload resource MAY return a `308 (Permanent Redirect)` status code and clients SHOULD use new permanent URI for subsequent requests. If the client receives a `307 (Temporary Redirect)` response to an offset retrieval ({{offset-retrieving}}) request, it MAY apply the redirection directly in an immediate subsequent upload append ({{upload-appending}}).
 
+# Subsequent Resources
+
+The server might process the uploaded data and make its results available in another resource during or after the upload. This subsequent resource is different from the upload resource created by the upload creation request ({{upload-creation}}). The subsequent resource does not handle the upload process itself, but instead facilitates further interaction with the uploaded data. The server MAY indicate the location of this subsequent resource by including the `Content-Location` header field in informational or final responses generated while creating ({{upload-creation}}), appending to ({{upload-appending}}), or retrieving the offset ({{offset-retrieving}}) of an upload. For example, a subsequent resource could allow the client to fetch information extracted from the uploaded data.
+
 # Security Considerations
 
 The upload resource URL is the identifier used for modifying the upload. Without further protection of this URL, an attacker may obtain information about an upload, append data to it, or cancel it. To prevent this, the server SHOULD ensure that only authorized clients can access the upload resource. In addition, the upload resource URL SHOULD be generated in such a way that makes it hard to be guessed by unauthorized clients.
@@ -517,7 +521,7 @@ The authors would like to thank Mark Nottingham for substantive contributions to
 ## Since draft-ietf-httpbis-resumable-upload-03
 {:numbered="false"}
 
-None yet.
+* Add note about `Content-Location` for referring to subsequent resources.
 
 ## Since draft-ietf-httpbis-resumable-upload-02
 {:numbered="false"}