# Page Not Found

The URL `topics/environment-topic-catalogue/inserting-and-deleting-messages` does not exist.

You might be looking for one of these pages:
- [Inserting & deleting data](https://docs.lenses.io/latest/user-guide/using/using-sql-to-query-kafka/inserting-and-deleting-data.md)
- [Creating & deleting Kafka topics](https://docs.lenses.io/latest/user-guide/using/using-sql-to-query-kafka/creating-and-deleting-kafka-topics.md)
- [Registering External Apps in Lenses](https://docs.lenses.io/latest/user-guide/using/register-your-own-applications/registering-external-apps-in-lenses.md)
- [Filtering & Joins](https://docs.lenses.io/latest/user-guide/using/tutorials/sql-processors/filtering-and-joins.md)
- [Controlling AVRO record names and namespaces](https://docs.lenses.io/latest/user-guide/using/tutorials/sql-processors/data-formats/controlling-avro-record-names-and-namespaces.md)

## How to find the correct page

1. **Browse the full index**: [/sitemap.md](https://docs.lenses.io/latest/sitemap.md) - Complete documentation index
2. **View the full content**: [/llms-full.txt](https://docs.lenses.io/latest/llms-full.txt) - Full content export

## Tips for requesting documentation

- For markdown responses, append `.md` to URLs (e.g., `/latest/user-guide/using/using-sql-to-query-kafka/inserting-and-deleting-data.md`)
- Use `Accept: text/markdown` header for content negotiation