Submitting the Final Paper to a Publisher
Many publishers ask that you submit an electronic copy of your paper in addition to a printed copy. Because the field codes in your document may be incompatible with the publishing software, you may be asked to submit a copy of your paper without field codes, as described in Removing Field Codes.
If your publisher uses EndNote, they may ask you to leave the field codes intact, enabling them to easily make changes to the citations or bibliography, if needed.