Non-standard Status Codes

[ibnesayeed]

Find up to two "in the wild" examples of different response codes not defined in an RFC (e.g., 299 or 999). Standard HTTP status codes and their corresponding RFCs are listed in the HTTP Status Code Registry

[calebkbrad]

Linkedin returns a 999 response code on requests to company pages.

curl -IL https://www.linkedin.com/company/google
HTTP/2 999
cache-control: no-cache, no-store
pragma: no-cache
content-length: 1530
content-type: text/html
expires: Thu, 01 Jan 1970 00:00:00 GMT
set-cookie: trkCode=bf; Max-Age=5
set-cookie: trkInfo=AQFApoDF3kX9eAAAAYTL-f1I0ayw-63c2kjvEckTYJRxyqyKZ58TXG0jiYAOd8U-6iZNNKoGKVL2T-6vz0PJohh8c_kMPDaAF2_UzrOXymft0kRNnbKL54XOHCB_OQDx8mrW4sM=; Max-Age=5
set-cookie: rtc=AQExffjznafMhwAAAYTL-f1IGbFokGOQVaDMVQt1ERD7g_ggb5tU71K_AQ-G8yIku1UtuRLe8J4M5P3n5wdam0rYDtvdlgXDEIxHaTc8iXzZLLnJjUw_HB10s-fqb5blNK9XB-HcqIz9yX-P0Ky_CQM0tRiAaflm5qDQxWXT-Wy47WMTjfmlpFqSbfay-KWffSFOXnvFcoBxNsyT; Max-Age=120; path=/; domain=.linkedin.com
x-li-fabric: prod-lva1
x-li-pop: afd-prod-lva1-x
x-li-proto: http/2
x-li-uuid: AAXuvMiTSl/GAFPy84LsuA==
x-cache: CONFIG_NOCACHE
x-msedge-ref: Ref A: A2404774D439458FBF5D5BD5AEF821CC Ref B: BL2AA2030106031 Ref C: 2022-12-01T04:37:49Z
date: Thu, 01 Dec 2022 04:37:49 GMT