Note that you can NOT set arbitrary response codes with this function, only those that are known to PHP (or the SAPI PHP is running on).
The following codes currently work as expected (with PHP running as Apache module):
200 – 208, 226
300 – 305, 307, 308
400 – 417, 422 – 424, 426, 428 – 429, 431
500 – 508, 510 – 511
Codes 0, 100, 101, and 102 will be sent as "200 OK".
Everything else will result in "500 Internal Server Error".
If you want to send responses with a freestyle status line, you need to use the `header()` function:
<?php header("HTTP/1.0 418 I'm A Teapot"); ?>
