As a SiteCatalyst admin user I would like to delete all values for a certain column on a eVar classification when I delete it in the interface. The current functionality actually just "hides" them until a new column is created. I will try to explain this issue with scenario below.
A user sets up conversion classifications with 2 data columns (column 1 and column 2) on one eVar inside SiteCatalyst admin interface. Values are being collected on this eVar and are used as keys in the classifications file. The user classifies all collected keys with corresponding values in the two data columns. Later the user decides to get rid of column 2 so he deletes it in the admin user interface. After a while a new column (column 3) is created on this eVar classification. This behavior will cause all old values that were stored in column 2 to be automatically filled in to the new column (column 3) for each key.
There is a workaround for this by adding ~empty~ to all keys in without any value in the new column, however, this is not a optimal workflow since you basically have to keep track of all old columns. When I delete a column in the interface all values in that column should be deleted along with it.