In the FD form, the Comment property contains comments pertaining to the data item defined by this row in the FD form. The comment is changed by clicking in the grid cell. See Specifying Comments for more information.
This property is totally owned by the catalog developer for use in the Designer. It is a good place to maintain a user-friendly definition of the data item. Another use of this property might be to discuss the uses of a data item that may not be obvious.