The standard Lower case function is supported for converting all characters in an expression to lower case. It is valid only if the expression evaluates to a character data type with the LATIN character set. The SQL generated is LOWER (expression) and the type returned is that of the expression. When dragging a Lower operator into a variable, the following tree element is created.
Variable Creation > Input > Variables: SQL Elements pane - String Functions > Lower
Columns and/or other expressions can be moved into the (empty) branches of the tree.
There are no special properties for the Lower operator.