remove a field that site visitor fills out when they add items but the column still exists

Hi,

I have a document library with a workflow running. I would like to remove a field that the site visitor fills out when they will add items, but I do not want to delete the column. I need the column for information that will be filled in later in the workflow not when the document will be initally uplaoded. I know it is possible, but do not remember. 

Thanks.

AT