Variations must be supplied inside []
[hello|world] will produce 2 lines:
hello
world
When you want to add optional variation add an empty variant inside [].
You will have to add spaces for each non empty variation and remove them from the outside if you want sentences to look good:
[|hello ]world produces:
world
hello world
If you don't rearrange spaces you will get:
[|hello] world:
world
hello world