 Welcome to the final week of our authority control class. So far we've been talking about how to use an authority file in order to select the authority record for the correct access point to use in a catalog record. In this session we're going to talk a little bit about maintenance of an authority file to make sure everything stays up to date and is pretty accurate. So one way to maintain your authority file is to keep track of headings that are either changed or deleted, canceled by the Library of Congress. And you can do this by periodically checking the approved lists of changed headings. The URL there says weekly lists, but they really these days come out more roughly monthly, I would say. They used to be weekly lists, but they've cut back. But these will tell you things that have changed. And then you can see if you have any of those headings in your catalog and download the new authority records that you need to. For example, recently the Library of Congress has changed all of their headings referring to insurance from inverted headings, so insurance, automobile. They've changed it to direct headings like automobile insurance. So as those changes came through, I would note them and see which ones we had in our catalog and download new authority records for those changed headings. Other than keeping up with changed headings, another thing you might want to do in order to clean up your authority file would be the deletion of authority records that are no longer used in any of the catalog records. For example, let's say you used to have books in your library about the Apple II e-computer and you've gotten rid of those from your collection because you have more up-to-date computer resources. So you might find that a subject heading for the Apple II e-computer no longer has any big records attached to it. And so if your system has a way to run a report on this and find out which authority records are unattached, if you have the time, that could be another way to clean up your authority file.