The Accept-Ranges response-header field allows the server to indicate its acceptance of range requests for a resource:
Accept-Ranges = "Accept-Ranges" ":" acceptable-ranges acceptable-ranges = 1#range-unit | "none"
Origin servers that accept byte-range requests MAY send
but are not required to do so. Clients MAY generate byte-range requests without having received this header for the resource involved.
Servers that do not accept any kind of range request for a resource MAY send
to advise the client not to attempt a range request.