All search fields are in a single group and are not marked as being strictly for authorities or bibliographic records. On the search engine configuration page, when adding mappings to either the bibliographic records tab or the authorities tab, all search fields are available from the drop down menu at the bottom of the page. It would be really nice if there was a way to distinguish between the two groups of search fields so that these drop down menus would only show the fields for that record type.

An alternative might be to reconfigure the way this page displays. Show the tables in a collapsed view based on search field. Expand a search field to see its mappings along with an empty field with "+ Add". This solution would allow a user to add mappings under the appropriate search field without having to manually select the field from a drop down.This would also make it easier to double-check to make sure you're entering the correct mapping since you'd be entering it in context, instead of at the bottom of a long list.