"og:description" content="$description$" /&gt;$endif$
$if(github-repo)$&lt;meta name="github-repo" content="$github-repo$" /&gt;$endif$
```

.footnote[
[default.html](https://github.com/rstudio/bookdown/blob/dda5f5a220058271a43ba8b81c6e6859ae3b9815/inst/templates/default.html)
]

???

This is the default.html template for our book's metadata. Some are static, like the character set. But others, like the last 4 here, are actually pulling values from our index YAML. 

So you can see that if there is a url spe