64 services carry this tag in their source record. Tags come from the provider, not from us — a tag is a claim about what the service does, not proof that it does it well.
HTTP 428 Precondition Required: what it means (conditional headers required), what a client should do (add If-Match), the class it belongs to, whether it is retryable and idempotency-safe, the defining RFC, and common ca...
HTTP 429 Too Many Requests: what it means (rate limited), what a client should do (wait Retry-After, then retry), the class it belongs to, whether it is retryable and idempotency-safe, the defining RFC, and common causes...
HTTP 431 Request Header Fields Too Large: what it means (headers too big), what a client should do (shrink cookies/headers), the class it belongs to, whether it is retryable and idempotency-safe, the defining RFC, and co...
HTTP 451 Unavailable For Legal Reasons: what it means (blocked by law/takedown), what a client should do (do not retry), the class it belongs to, whether it is retryable and idempotency-safe, the defining RFC, and common...
HTTP 500 Internal Server Error: what it means (server bug), what a client should do (retry with backoff), the class it belongs to, whether it is retryable and idempotency-safe, the defining RFC, and common causes. Precis...
HTTP 501 Not Implemented: what it means (method unsupported by server), what a client should do (do not retry), the class it belongs to, whether it is retryable and idempotency-safe, the defining RFC, and common causes....
HTTP 502 Bad Gateway: what it means (upstream failed), what a client should do (retry with backoff), the class it belongs to, whether it is retryable and idempotency-safe, the defining RFC, and common causes. Precise one...
HTTP 503 Service Unavailable: what it means (overloaded or down for maintenance), what a client should do (wait Retry-After), the class it belongs to, whether it is retryable and idempotency-safe, the defining RFC, and c...
HTTP 504 Gateway Timeout: what it means (upstream timed out), what a client should do (retry with backoff), the class it belongs to, whether it is retryable and idempotency-safe, the defining RFC, and common causes. Prec...
HTTP 505 HTTP Version Not Supported: what it means (protocol version rejected), what a client should do (downgrade), the class it belongs to, whether it is retryable and idempotency-safe, the defining RFC, and common cau...
HTTP 506 Variant Also Negotiates: what it means (negotiation misconfigured), what a client should do (report), the class it belongs to, whether it is retryable and idempotency-safe, the defining RFC, and common causes. P...
HTTP 507 Insufficient Storage: what it means (WebDAV: out of space), what a client should do (free space), the class it belongs to, whether it is retryable and idempotency-safe, the defining RFC, and common causes. Preci...
HTTP 508 Loop Detected: what it means (WebDAV: infinite loop), what a client should do (fix bindings), the class it belongs to, whether it is retryable and idempotency-safe, the defining RFC, and common causes. Precise o...
HTTP 510 Not Extended: what it means (extension required), what a client should do (add extension), the class it belongs to, whether it is retryable and idempotency-safe, the defining RFC, and common causes. Precise one-...
HTTP 511 Network Authentication Required: what it means (captive portal), what a client should do (log in to the network), the class it belongs to, whether it is retryable and idempotency-safe, the defining RFC, and comm...
HTTP status code explained: the standard reason phrase, what it means and what a client should do, for every common code, or the full list for a class like '4xx'. $0.01 per lookup.