The transfer codings the user agent is willing to accept.
Fastly reads this header from requests and writes it into requests. It is defined by an external standard.
TE header field in a request indicates what transfer codings, besides chunked, the client is willing to accept in response, and whether or not the client is willing to accept trailer fields in a chunked transfer coding.
TE field-value consists of a comma-separated list of transfer coding names, each allowing for optional parameters (as described in Section 4 of RFC 7230), and/or the keyword
trailers. A client MUST NOT send the chunked transfer coding name in
TE; chunked is always acceptable for HTTP/1.1 recipients.