HTTP registry: http_protocol_error
The intermediary encountered an HTTP protocol error when communicating with the next hop. This error should only be used when a more specific one is not defined.
Proxy and gateway values describe processing across trust boundaries where fields, authority, and framing may be transformed. http_protocol_error is registered in HTTP Proxy Error Types. Defining reference: rfc9209.
Identifier (http)
http_protocol_error
The intermediary encountered an HTTP protocol error when communicating with the next hop. This error should only be used when a more specific one is not defined.
Strip hop-by-hop data, normalize framing, trust forwarded metadata only from configured proxies, and avoid exposing topology or credentials.
This registry value is currently marked active by IANA. Follow the defining specification before sending, accepting, or proxying it.
IANA registry: http-proxy-status/http-proxy-error-types
Registry reference: rfc9209
Sources