How to Hide a List Column
Sign in or go to the 'Organization and Projects' page.
Click on the document where you want to hide a column.
Click the menu button in the column header of the column you want to hide.
Click the 'Hide Column' menu item in the drop down menu.
Note that the column, and its data, is are not deleted. It is just hidden. If you create a new column bound to the same underlying column the data will still be there.