More Information

bulk_edit_custom_box is an action that lets plugin print inputs for custom columns when bulk editing. This action is called one time for each custom column. Custom columns are added with the manage_edit-${post_type}_columns filter. To save the data from the custom inputs, hook the save_post action.

Note that the action function is passed neither the post ID nor any existing value for the column.

See quick_edit_custom_box for basis.