I suggest to implement the following feature:
Enhance ITableColumn interface with comment property.
A typical use case might be:
In complex reports with many fields or variables, sometimes there are so many fields it is not easy to pick the right one. If ITableColumn would be extended with a comment property I can describe the purpose of the field. LL could display this information when showing the tooltip of the mouse hovering over the fields or variables.
Even better would be, if the comment supports some kind of markup or is capable of handling RTF-text, so I could use bold, italic attributes and paragraphs. LL already uses some kind of Tooltips in his Ribbons, so this should be possible.
Even cooler would be, if there is a placeholder of the current sample value which LL uses for the layout-preview, so I can even better describe the purpose of the field using an example.
I know I can already group fields and variables hierarchical. I also can search for fields. But having a tooltip with a description makes life far more pleasant.