Hein has just announced that that all the collections in HeinOnline will now return faceted search results -- an enhancement that was first introduced with the Law Journal Library in January of 2010.
What are faceted search results? When performing a field search or advanced search in any collection, you will see a menu called "Refine Your Search" on the left sidebar when you are viewing your results. Depending on the collection you are in and the terms searched, your results will be grouped by categories such as title, authors, publications, dates, and other fielded subsets of information. You can focus your search by selecting one of these "faceted" categories.
If you have any questions about faceted searching, please don't hesitate to ask one of the reference librarians.