The formatting category includes the following blocks:

The code block starts with
<!-- wp:code -->
<?php echo 'Hello World'; ?>

The classic block can have almost anything in it.

---

a heading

…

Headings

Header one

Header two

Header three

Header four

Header five

Header six

Blockquotes

Single line blockquote:

Stay hungry. Stay foolish.

Multi line blockquote with a cite reference:

The HTML <…