How do I create an accordion or collapse in Redmine?

How do I create an accordion or collapse effect in Redmine?

Additional Posts

In the body of the ticket, add the following:

{{collapse(This is the error message)
Error message here with lots of text
}}

Now in the body you'll see a "link" that says "This is the error message."

When clicked the message will expand. Anything after the closing parenthesis and the double mustache is the collapsable content.

Looks like there are a number of macros available to us that are not outlined in the traditional markdown docs: https://support.blendinteractive.com/help/en/wiki_syntax_detailed_textile.html#12
@TylerHarms Yup, that's where I found these.