Any reference in a Markdown document may use the annotated reference syntax to refer to a global logical anchors.
{{<name>}}
where name follows the name syntax for anchors.
A typical link, like the one above, looks like this:
[name syntax]({{name}})
Anchors are just defined by using the reference syntax outside the Markdown reference syntax.
For example
{{my-chapter}}
# My Chapter
It might be placed anywhere in a markdown document, therefore, it is possible to link to any location, not only section headers.
If placed directly before or after a Markdown section heading
(and the option --headings) is given, no explicit anchor is generated,
but the Markdown anchor name is used for the references.
This keeps the generated file viewable by Markdown viewers not able to
work with anchors.