Inline code fragment.

echo "Hello, world."

Programming constant.

INT_MAX

Email address.

<john_doe@example.com>

Literal value.

1.2345

String of formatting markup. Something other than a tag.

[link](http://example.com)

Name replace by a value before processing. E.g, a C preprocessor #defined symbol.

MAXPATHLEN

Markup instruction. E.g., in SGML, XML, HTML, etc.

para

<para>

</para>

role

String with an assigned meaning. A token value is categorized into one of several token names.

if

Uniform Resource Identifier.

http://www.example.com/some_path