# Chapter 1

[This links to itself](./chapter_1.md)
[This links to itself using the HTML extension](./chapter_1.html)

[Link to a nested directory](nested/README.md). You can also link to
[the directory](nested/) directly and it'll be rewritten to `README.md`.

## Subheading

[And also external web pages](https://www.google.com/)

[Some web links require additional HTTP headers](https://crates.io/crates/mdbook-linkcheck)

[You can also blacklist URLs by regex](https://nonexistent.forbidden.com/)