# Page Not Found

The URL `content/en/part4.html` does not exist.

You might be looking for one of these pages:
- [Updating HTTP](https://http2-explained.haxx.se/en/part4.md)
- [Background](https://http2-explained.haxx.se/en/part1.md)
- [HTTP Today](https://http2-explained.haxx.se/en/part2.md)
- [Things done to overcome latency pains](https://http2-explained.haxx.se/en/part3.md)
- [http2 concepts](https://http2-explained.haxx.se/en/part5.md)

## How to find the correct page

1. **Browse the full index**: [/sitemap.md](https://http2-explained.haxx.se/sitemap.md) - Complete documentation index
2. **View the full content**: [/llms-full.txt](https://http2-explained.haxx.se/llms-full.txt) - Full content export

## Tips for requesting documentation

- For markdown responses, append `.md` to URLs (e.g., `/en/part4.md`)
- Use `Accept: text/markdown` header for content negotiation