20 plain-English definitions, from 301 redirect to 7z archive. Terms with a link have a full explanation with a Jersey example. To search every term, go back to the Jargon Buster.
A 301 redirect is an HTTP response used for a permanent move to another URL. It helps visitors and search engines follow the replacement address. It does not guarantee unchanged rankings. Plan it when a business redesign changes important page addresses, and test the destination before launch.
Also called: permanent redirect
A 302 redirect is an HTTP response indicating a temporary move. It can suit a short-lived routing change, while a lasting page move usually needs an appropriate permanent redirect. Choose the status to reflect the actual situation rather than treating every redirect as interchangeable.
Also called: temporary redirect
HTTP 401 means the request lacks valid authentication credentials for the target resource. It is different from a missing page. When a website integration returns this response, review its supported authentication and account access without exposing secret credentials in logs, screenshots or public code.
Also called: 401 Unauthorized
HTTP 403 means the server understood the request but refuses to fulfil it. Access permissions or other restrictions may be involved. It is different from HTTP 401. Diagnose the actual service and account permissions rather than assuming that refreshing the page will change the access decision.
Also called: 403 Forbidden
A 404 error means the server could not find the resource at the requested address. It often follows an outdated link or a deleted page. A helpful error page gives visitors another route; a moved service page may need a redirect to its relevant replacement.
Also called: page not found, 404
HTTP 408 Request Timeout indicates that the server did not receive a complete request within the time it was prepared to wait. It can also concern an unused connection. Record the actual request and server context; this status is different from a gateway waiting too long for an upstream response.
Also called: 408 Request Timeout
A 410 response indicates that a resource is gone and is likely to remain unavailable. It is different from redirecting to a relevant replacement. When removing business content, decide whether customers need a replacement page, an explanation or a deliberate removal response.
Also called: gone status
HTTP 411 Length Required indicates that the server refuses a request without the required Content-Length information. It concerns request framing, rather than the length of a page headline. Have the integration maintainer review the supported request format and client behaviour instead of changing website copy.
Also called: 411 Length Required
HTTP 412 Precondition Failed indicates that a condition supplied with a request was not met. It can arise when a client tries to modify a resource using an outdated version condition. Review the current resource and supported update process instead of repeatedly sending the unchanged request.
Also called: 412 Precondition Failed
HTTP 415 Unsupported Media Type indicates that the server rejects the request’s content format. The declared content type, encoding or actual content can be relevant. Ask the integration maintainer to compare the submitted data with the endpoint’s documented requirements; this is separate from a website image failing to display.
Also called: 415 Unsupported Media Type
HTTP 422 Unprocessable Content indicates that the server understands the content type and syntax but cannot process the contained instructions. Review the response details and endpoint requirements. Repeating the same request unchanged normally leaves the underlying problem unresolved, so the application should explain the relevant correction.
Also called: 422 Unprocessable Content, 422 Unprocessable Entity
HTTP 425 Too Early indicates that the server is unwilling to risk processing a request that could be replayed, in the context of early data. It is separate from ordinary rate limiting. Have the protocol or integration maintainer review the actual early-data handling and supported retry behaviour.
Also called: 425 Too Early
HTTP 426 Upgrade Required indicates that the server refuses the current protocol but may accept the request using a different protocol identified in its Upgrade header. It is a protocol requirement, rather than a request to buy a hosting upgrade. Review the maintained client and service compatibility.
Also called: 426 Upgrade Required
HTTP 429 means too many requests have been sent within a period under the server’s rules. It commonly indicates rate limiting. An integration should handle the provider’s supported retry instructions and avoid immediately repeating requests in a way that makes the overload worse.
Also called: 429 Too Many Requests
HTTP 431 Request Header Fields Too Large indicates that the server rejects request headers because their size exceeds its accepted limits. The total headers or an individual field can be responsible. Ask the maintainer to identify the relevant field and context; the status does not by itself establish a universal cookie or browser fix.
Also called: 431 Request Header Fields Too Large
HTTP 451 Unavailable For Legal Reasons indicates that a requested resource is unavailable because of legal reasons. It describes the response received, rather than establishing every fact behind the restriction. Retain the provider’s explanation and relevant context, and contact the responsible service when reviewing the affected business resource.
Also called: 451 Unavailable For Legal Reasons
A 500 response means the server encountered an unexpected problem and could not complete the request. It does not identify the cause by itself. Record the affected page and action, then ask the responsible supplier to inspect the service and its diagnostic information.
Also called: internal server error
A 503 response says a service is currently unavailable, for example during overload or maintenance. The website should give a clear temporary explanation where possible. Staff need to know which provider owns the fault and how to check when the service has recovered.
Also called: service unavailable
HTTP 507 Insufficient Storage indicates that the server cannot complete the operation because it lacks required storage or relevant resources. It is different from a request exceeding a content-size limit. Ask the maintainer to investigate the actual service limits and verify the intended operation after addressing the cause.
Also called: 507 Insufficient Storage
A 7z archive uses the archive format documented by the 7-Zip project. The format supports different compression methods and optional encryption arrangements. Check the actual package and recipient support; the format name alone does not show which options were used, whether contents are protected or whether the handover includes the required files.
Also called: 7z file
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