HTTP status codes:

Here is the list of all the valid HTTP - status codes, and the corresponding phrases, that PHP scripting language can generate when using the $http_response_code parameter in the header() function.
The invalid codes (for example: 199) generate a 500 Internal Server Error response.

To send a specific HTTP status code, the prototype of the header() function is:
void header(string $string, bool $replace, int $http_response_code)

The 3 parameters are:

string $string:
Several cases:

an empty string: ''

we have to AVOID this case, as then the function does NOT work!

a NOT empty string, which does NOT contain any colon ':' character:

the more usual case, to send the desired status code and phrase

a NOT empty string, which contains a colon ':' character inside:

a useful case, to send the desired status code and phrase AND a response header
(see examples below)
bool $replace: always TRUE
int $http_response_code: an integer, the desired status code, in the range: from 100 to 510

Examples of use:

The string parameter does not contain any colon character: /* The server will ouput: * the response status "HTTP/1.1 204 No Content" */ header('x', TRUE, 204);
The string parameter contains a response header, of which the syntax is: <string header-name><char colon><char space><string header-value>: /* The server will ouput: * the response status "HTTP/1.1 405 Method Not Allowed" * and the response header "Allow: GET, HEAD" */ header('Allow: GET, HEAD', TRUE, 405);

List of status codes and phrases generated by PHP:

›100 Continue
›101 Switching Protocols
›102 Processing

›119 Too Many Requests

›134 Too Many Requests

›143 Too Many Requests
›144 Too Many Requests
›145 Too Many Requests

›147 Too Many Requests
›148 Too Many Requests

›169 Too Many Requests

›188 Too Many Requests
›189 Too Many Requests

›200 OK
›201 Created
›202 Accepted
›203 Non-Authoritative Information
›204 No Content
›205 Reset Content
›206 Partial Content
›207 Multi-Status
›208 Already Reported

›221 Too Many Requests

›226 IM Used

›233 Too Many Requests
›234 Too Many Requests
›235 Too Many Requests
›236 Too Many Requests
›237 Too Many Requests
›238 Too Many Requests
›239 Too Many Requests
›240 Too Many Requests
›241 Too Many Requests
›242 Too Many Requests
›243 Too Many Requests
›244 Too Many Requests
›245 Too Many Requests
›246 Too Many Requests
›247 Too Many Requests
›248 Too Many Requests
›249 Too Many Requests
›250 Too Many Requests
›251 Too Many Requests
›252 Too Many Requests
›253 Too Many Requests
›254 Too Many Requests

›256 Too Many Requests
›257 Too Many Requests
›258 Too Many Requests

›260 Too Many Requests

›262 Too Many Requests
›263 Too Many Requests
›264 Too Many Requests

›266 Too Many Requests

›268 Too Many Requests
›269 Too Many Requests
›270 Too Many Requests
›271 Too Many Requests
›272 Too Many Requests

›274 Too Many Requests
›275 Too Many Requests
›276 Too Many Requests
›277 Too Many Requests
›278 Too Many Requests

›280 Too Many Requests
›281 Too Many Requests
›282 Too Many Requests
›283 Too Many Requests
›284 Too Many Requests
›285 Too Many Requests
›286 Too Many Requests
›287 Too Many Requests
›288 Too Many Requests
›289 Too Many Requests
›290 Too Many Requests
›291 Too Many Requests
›292 Too Many Requests
›293 Too Many Requests
›294 Too Many Requests
›295 Too Many Requests
›296 Too Many Requests
›297 Too Many Requests
›298 Too Many Requests

›300 Too Many Requests
›301 Too Many Requests
›302 Too Many Requests
›303 See Other
›304 Too Many Requests
›305 Use Proxy
›306 Too Many Requests
›307 Too Many Requests
›308 Too Many Requests

›310 Too Many Requests

›312 Too Many Requests
›313 Too Many Requests
›314 Too Many Requests
›315 Too Many Requests
›316 Too Many Requests

›318 Too Many Requests
›319 Too Many Requests
›320 Too Many Requests
›321 Too Many Requests
›322 Too Many Requests
›323 Too Many Requests
›324 Too Many Requests

›326 Too Many Requests
›327 Too Many Requests
›328 Too Many Requests
›329 Too Many Requests
›330 Too Many Requests
›331 Too Many Requests
›332 Too Many Requests
›333 Too Many Requests
›334 Too Many Requests
›335 Too Many Requests
›336 Too Many Requests
›337 Too Many Requests
›338 Too Many Requests
›339 Too Many Requests
›340 Too Many Requests
›341 Too Many Requests
›342 Too Many Requests
›343 Too Many Requests
›344 Too Many Requests

›350 Too Many Requests
›351 Too Many Requests
›352 Too Many Requests
›353 Too Many Requests
›354 Too Many Requests

›356 Too Many Requests
›357 Too Many Requests

›359 Too Many Requests
›360 Too Many Requests
›361 Too Many Requests
›362 Too Many Requests
›363 Too Many Requests
›364 Too Many Requests
›365 Too Many Requests
›366 Too Many Requests
›367 Too Many Requests
›368 Too Many Requests
›369 Too Many Requests
›370 Too Many Requests
›371 Too Many Requests
›372 Too Many Requests
›373 Too Many Requests
›374 Too Many Requests
›375 Too Many Requests
›376 Too Many Requests
›377 Too Many Requests
›378 Too Many Requests
›379 Too Many Requests
›380 Too Many Requests
›381 Too Many Requests
›382 Too Many Requests
›383 Too Many Requests

›385 Too Many Requests
›386 Too Many Requests

›393 Too Many Requests
›394 Too Many Requests
›395 Too Many Requests
›396 Too Many Requests
›397 Too Many Requests
›398 Too Many Requests
›399 Too Many Requests
›400 Too Many Requests
›401 Unauthorized
›402 Too Many Requests
›403 Too Many Requests
›404 Too Many Requests
›405 Too Many Requests
›406 Too Many Requests
›407 Proxy Authentication Required
›408 Request Timeout
›409 Too Many Requests
›410 Too Many Requests
›411 Too Many Requests
›412 Too Many Requests
›413 Request Entity Too Large
›414 Too Many Requests
›415 Too Many Requests
›416 Too Many Requests
›417 Too Many Requests
›418 Too Many Requests
›419 Too Many Requests
›420 Too Many Requests
›421 Too Many Requests
›422 Too Many Requests
›423 Too Many Requests
›424 Failed Dependency
›425 Too Many Requests
›426 Too Many Requests
›427 Too Many Requests
›428 Too Many Requests
›429 Too Many Requests
›430 Too Many Requests
›431 Too Many Requests
›432 Too Many Requests
›433 Too Many Requests
›434 Too Many Requests
›435 Too Many Requests
›436 Too Many Requests
›437 Too Many Requests
›438 Too Many Requests
›439 Too Many Requests
›440 Too Many Requests
›441 Too Many Requests
›442 Too Many Requests
›443 Too Many Requests
›444 Too Many Requests
›445 Too Many Requests
›446 Too Many Requests
›447 Too Many Requests
›448 Too Many Requests
›449 Too Many Requests
›450 Too Many Requests
›451 Unavailable For Legal Reasons

›455 Too Many Requests
›456 Too Many Requests

›459 Too Many Requests

›461 Too Many Requests
›462 Too Many Requests
›463 Too Many Requests
›464 Too Many Requests
›465 Too Many Requests
›466 Too Many Requests
›467 Too Many Requests
›468 Too Many Requests
›469 Too Many Requests
›470 Too Many Requests
›471 Too Many Requests
›472 Too Many Requests
›473 Too Many Requests
›474 Too Many Requests
›475 Too Many Requests
›476 Too Many Requests
›477 Too Many Requests
›478 Too Many Requests
›479 Too Many Requests
›480 Too Many Requests
›481 Too Many Requests
›482 Too Many Requests
›483 Too Many Requests
›484 Too Many Requests
›485 Too Many Requests
›486 Too Many Requests
›487 Too Many Requests
›488 Too Many Requests
›489 Too Many Requests
›490 Too Many Requests

›492 Too Many Requests
›493 Too Many Requests
›494 Too Many Requests

›500 Internal Server Error
›501 Too Many Requests
›502 Too Many Requests
›503 Too Many Requests
›504 Too Many Requests
›505 Too Many Requests
›506 Too Many Requests
›507 Too Many Requests
›508 Too Many Requests
›509 Too Many Requests
›510 Too Many Requests
›511 Too Many Requests
›512 Too Many Requests
›513 Too Many Requests
›514 Too Many Requests
›515 Too Many Requests
›516 Too Many Requests
›517 Too Many Requests
›518 Too Many Requests
›519 Too Many Requests
›520 Too Many Requests

›522 Too Many Requests

›529 Too Many Requests
›530 Too Many Requests
›531 Too Many Requests
›532 Too Many Requests
›533 Too Many Requests
›534 Too Many Requests
›535 Too Many Requests
›536 Too Many Requests
›537 Too Many Requests
›538 Too Many Requests
›539 Too Many Requests
›540 Too Many Requests
›541 Too Many Requests
›542 Too Many Requests
›543 Too Many Requests
›544 Too Many Requests
›545 Too Many Requests
›546 Too Many Requests

›548 Too Many Requests
›549 Too Many Requests
›550 Too Many Requests
›551 Too Many Requests
›552 Too Many Requests
›553 Too Many Requests
›554 Too Many Requests
›555 Too Many Requests
›556 Too Many Requests
›557 Too Many Requests
›558 Too Many Requests
›559 Too Many Requests
›560 Too Many Requests
›561 Too Many Requests

›582 Too Many Requests
›583 Too Many Requests
›584 Too Many Requests
›585 Too Many Requests

Get the list in these other formats:

Format	Description
Text	code[HT]phrase[LF] ...
CSV	code,"phrase"[LF] ...
XML	<?xml version="1.0" encoding="UTF-8"?> <http-status-codes> <status> <code>code</code> <phrase>phrase</phrase> </status> ... </http-status-codes>
PHP	$a_http_status_codes = array( code => 'phrase', ... );
Javascript	var oHttpStatusCodes = { code: 'phrase', ... };
JSON	{"oHttpStatusCodes": { "code": "phrase", ... }}
MySQL	INSERT INTO `http_status_codes` (`code`, `phrase`) VALUES (code, 'phrase'), ...;

Hypertext Transfer Protocol:

Resource	Description
RFC 2616 (HTML)	HTTP/1.1
RFC 2616 (Text)	HTTP/1.1
RFC 4918 (HTML)	HTTP Extensions for Web Distributed Authoring and Versioning
RFC 4918 (Text)