# Knowledge Base | UTNOR

## Docs

- [Client Error Response Format](https://docs.utnor.com/getting-started/client-error-response-format.md): Standard JSON format used by UTNOR for client-side error responses.
- [Getting Started with UTNOR](https://docs.utnor.com/getting-started/index.md): Learn how to navigate UTNOR documentation, choose the right starting path, and understand how the platform is structured.
- [Tool Ecosystem](https://docs.utnor.com/getting-started/tool-ecosystem.md): Explains how UTNOR tools are organized and how users should approach them.
- [UTNOR Overview](https://docs.utnor.com/getting-started/utnor-overview.md): Introduces UTNOR and explains how to approach the platform as a learning and experimentation environment.
- [Knowledge Base | UTNOR](https://docs.utnor.com/index.md): Official knowledge base for UTNOR tools, usage information.
- [Request & Response](https://docs.utnor.com/request-format.md): Learn how to send a request to Custom Status and understand exactly what the server returns in response.
- [EMPTY_REQUEST](https://docs.utnor.com/tools/status/errors/EMPTY_REQUEST.md): Occurs when the 'status' query parameter is missing or left empty.
- [PAGE_NOT_FOUND](https://docs.utnor.com/tools/status/errors/PAGE_NOT_FOUND.md): This error occurs when you access an endpoint that doesn’t exist.
- [RANGE_VIOLATION](https://docs.utnor.com/tools/status/errors/RANGE_VIOLATION.md): Occurs when the 'status' query parameter is outside the allowed range (200–599).
- [UNCAUGHT_RUNTIME_ERROR](https://docs.utnor.com/tools/status/errors/UNCAUGHT_RUNTIME_ERROR.md): Occurs when an unexpected server-side error happens during request processing.
- [INVALID_TYPE](https://docs.utnor.com/tools/status/errors/invalid-type.md): Occurs when the 'status' query parameter is not a valid positive integer.
- [SECURITY_VIOLATION](https://docs.utnor.com/tools/status/errors/security-violation.md): Occurs when a request is blocked due to security or abuse protection mechanisms.
- [Test](https://docs.utnor.com/tools/status/errors/testing_run_time.md)
- [Introduction & Overview](https://docs.utnor.com/tools/status/overview/about.md): Why Custom Status exists, what it does, and how it helps you observe real client-side behavior with predictable HTTP responses.
- [How it Works](https://docs.utnor.com/tools/status/overview/how-it-works.md): A simple look at how Custom Status behaves behind the scenes — without diving into internals.
- [Intended Use](https://docs.utnor.com/tools/status/overview/intended-use.md): Understand how Custom Status is used to observe and validate real client-side behavior across different HTTP status responses.
- [Security & Privacy](https://docs.utnor.com/tools/status/overview/security-and-privacy.md): How Custom Status handles data, boundaries, and responsible use.
- [Request & Response](https://docs.utnor.com/tools/status/usage/request-and-response.md): Learn how to send a request to Custom Status and understand exactly what the server returns in response.