Some query types for rule templates return a list of elements, for example the query "Dimension element like (list)". Variables with a list result can only be used in specific places in rules and require correct syntax. However, the Rule Editor still offers the variables (for example ${Elements}) in all places where variables can be selected, leading to possible syntax errors.
It would be nice to have a little more guidance for the user here; if some specific control doesn't support usage of lists, then the variable could be hidden in the dropdown.
