The instructions above the textarea in the WP forums states

Put code in between `backticks`.

People have hard time understanding and/or following this. Sometimes there’s <code>, [code] or just ‘. But this is definitely the cutest of them all:

‘backticks’
<object classid="…" width="320" height="256" codebase="…">
[…]
</object>
‘backticks’