How to use Variables?

[Rosko]

Evening All,

Sorry for my noob ignroance, I've tried to learn about Variables but I can't seem to get the grasp of it working.

https://help.trello.com/article/1157-variables

It says that Variables can be used in list names, card titles, card descriptions and comments, e.g.:

So as a quick test on the card description, I throw together a Variable to hopefully get the current value, but nothering happened?

OR... can these variables only be understood and used IN Butler?

Thanks

[Iain Dooley]

@Rosko yes these are only Butler variables