All 200s are successes. 200 ("OK") is the usual case. is_success (on the return value of getstore and getprint) checks for a return code in the 200s. But as moot mentioned, some servers return success (200) with an HTML message instead of a 404 (with or without an HTML message) when an file cannot be found. That's why I mentioned checking Content-Type in addition to the return code.