Documentation: Possible Typo in https://www.jetporch.com/playbooks/plays

I'm noticing that most tasks in the example playbooks start with a bang followed by the module name.

In the first code example under Playbook Syntax on https://www.jetporch.com/playbooks/plays, there appears a task called `!shell:` but it didn't work until I removed the colon. Is this a typo?