Reference is from RFC 2616 and is extended by RFC 2518, RFC 2817, RFC 2295, RFC 2774, RFC 4918, and other specifications. The red word represents a few of the more common status CODE
"Continue":
"101": Switching protocols
"102": Processing (WebDAV; RFC 2518)
"$": OK
"201": Created
"202": Accepted
"203": non-authoritative information (since http/1.1)
"204": No Content
"205": Reset Content
"206": Partial Content
"207": Multi-Status (WebDAV; RFC 4918)
"208": Already reported (WebDAV; RFC 5842)
"226": IM Used (RFC 3229)
"Multiple": Choices
"301": Moved Permanently
"302": Found
"303": See Other (since http/1.1)
"304": Not Modified
"305": Use Proxy (since http/1.1)
"306": Switch Proxy (no longer used)
"307": Temporary Redirect (since http/1.1)
"308": Permanent Redirect (experimental RFC; RFC 7238)
"$": 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 time-out
"409": Conflict
"410": Gone
"411": Length Required
"412": Precondition Failed
"413": Request Entity Too Large
"414": Request-uri Too Large
"415": Unsupported Media Type
"416": Requested range not satisfiable
"417": Expectation Failed
"418": I ' m a teapot (RFC 2324)
"419": Authentication Timeout (not in RFC 2616)
"420": Method Failure (Spring Framework)
"420": Enhance Your Calm (Twitter)
"421": There is too many connections from your Internet address (Unknown)
"422": Unprocessable Entity (WebDAV; RFC 4918)
"423": Locked (WebDAV; RFC 4918)
"424": Failed Dependency (WebDAV; RFC 4918)
"426": Upgrade Required (RFC 2817)
"428": Precondition Required (RFC 6585)
"429": Too many requests (RFC 6585)
"431": Request Header Fields Too Large (RFC 6585)
"A": Login Timeout (Microsoft)
"444": No Response (Nginx)
"449": Retry with (Microsoft)
"Blocked": by Windows parental Controls (Microsoft)
"451": Unavailable for Legal reasons (Internet draft)
"451": Redirect (Microsoft)
"494": Request Header Too Large (Nginx)
"495": Cert Error (Nginx)
"496": No Cert (Nginx)
"497": HTTP to HTTPS (Nginx)
"498": Token expired/invalid (ESRI)
"499": Client Closed Request (Nginx)
"499": Token required (ESRI)
"$": Internal Server Error
"501": Not implemented
"502": Bad Gateway
"503": Service unavailable
"504": Gateway time-out
"505": HTTP Version not supported
"506": Variant Also negotiates (RFC 2295)
"507": Insufficient Storage (WebDAV; RFC 4918)
"508": Loop detected (WebDAV; RFC 5842)
"509": Bandwidth Limit exceeded (Apache bw/limited extension)
"510": Not Extended (RFC 2774)
"511": Network authentication Required (RFC 6585)
"598": Network read timeout error (Unknown)
"599": Network Connect Timeout error (Unknown)
"Unparseable": Response Headers