Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
Early-Data header is set by an intermediary to indicate that the request has been conveyed in TLS early data, and also indicates that the intermediary understands the
425 (Too Early) status code.
Early-Data header is not set by the originator of the request (i.e., a browser).
|Header type||Request header|
|Forbidden header name||no|