cformat switch: @
For multi-level lists, a column must be defined using this type, and must also contain a digit indicating the hierarchical level of each row (0 through 63 with 0 being the top level.) Note that you would almost always want to also use the H code to hide this column, otherwise you will have a visible column containing the level indicators. Due to some internal complexities in the control, it may not be possible to hide the first column; to avoid this problem, make sure the @ column is not the first one defined.
The compound code @@ may be used in place of just @ to force the left/right arrow keys to always act as expand/contract/navigate keys, even if the XTF_LEFT, XTF_RIGHT, or XTF_EDITABLE flags are present. See XTREE Techniques - Mouse and Keyboard.
History
2023 August, A-Shell 1737: Increase maximum number of multi-level trees from nine to 63.