Comments within Guide use simple tags and begin with a ! prefix:
Use a - character after the start tag and before the end tag if the comment includes }} or other Guide tokens.
These examples exclude the content contained in the wrapping tags from displaying in any part of the message. This functionality differs from an HTML tag, which still renders and sends to the client.
Use commenting during the development of new messages. Comments allow for explanations of what tags should produce and provide a layer of troubleshooting when tags do not render as expected.