http status codes I still look up

the ones that show up in real bug reports, not the whole RFC.

01
200 OK
02
201 Created
you POSTed something and the server made a new resource. check the Location header
03
204 No Content
04
301 Moved Permanently
05
302 Found
temporary redirect, browsers still get this wrong sometimes
06
304 Not Modified
your cache is fine, stop asking
07
400 Bad Request
08
401 Unauthorized
confusing name - it actually means unauthenticated, not logged in at all
09
403 Forbidden
10
404 Not Found
11
409 Conflict
12
422 Unprocessable Content
syntax is fine, the data doesn't make sense. rails apps throw this constantly
13
429 Too Many Requests
rate limited. check for a Retry-After header before hammering it again
14
500 Internal Server Error
something broke and the server won't say what. check the logs, not the response
15
502 Bad Gateway
the proxy got a bad answer from whatever's behind it
16
503 Service Unavailable

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