Hypertext Transfer Protocol Response status codes. And dogs.

100 Continue 200 OK 201 Created 202 Accepted 203 Non-Authoritative Information 204 No Content 206 Partial Content 207 Multi-Status 208 Already Reported 226 IM Used 300 Multiple Choices 301 Moved Permanently 302 Found 303 See Other 304 Not Modified 305 Use Proxy 306 Switch Proxy 307 Temporary Redirect 308 Permanent Redirect 400 Bad Request 401 Unauthorized 402 Payment Required 403 Forbidden 404 Not Found 405 Method Not Allowed 406 Not Acceptable 407 Proxy Authentication Required 408 Request Timeout 409 Conflict 410 Gone 411 Length Required 412 Precondition Failed 413 Request Entity Too Large 414 Request-URI Too Long 416 Requested Range Not Satisfiable 417 Expectation Failed 418 I'm a teapot 420 Enhance Your Calm 422 Unprocessable Entity 423 Locked 424 Failed Dependency 425 Unordered Collection 426 Upgrade Required 429 Too Many Requests 431 Request Header Fields Too Large 444 No Response 450 Blocked by Windows Parental Controls 451 Unavailable For Legal Reasons 494 Request Header Too Large 500 Internal Server Error 501 Not Implemented 502 Bad Gateway 503 Service Unavailable 504 Gateway Timeout 506 Variant Also Negotiates 507 Insufficient Storage 508 Loop Detected 509 Bandwidth Limit Exceeded 510 Not Extended