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

The preformatted block.

The Road Not Taken

Robert Frost 
Two roads diverged in a yellow wood,
And sorry I could not travel both(\_/)
And be one traveler, long I stood (='.'=)
And looked down one as far as I could (")_(")
To where it bent in the undergrowth; 

Then took the other, as just as fair,
And having perhaps the better claim,|\_/|
Because it was grassy and wanted wear; / @ @ \
Though as for that the passing there( > º < )
Had worn them really about the same, `>>x<<´
 /O\
And both that morning equally lay
In leaves no step had trodden black.
Oh, I kept the first for another day!
Yet knowing how way leads on to way,
I doubted if I should ever come back.
I shall be telling this with a sigh
Somewhere ages and ages hence:
Two roads diverged in a wood, and I—
I took the one less traveled by,
And that has made all the difference.



and here's a line of some really, really, really, really long text, just to see how it is handled and to find out how it overflows;

The Verse block

A block for haiku? 
Why not? 
Blocks for all the things!