The documentation for OpenURL in FirstSearch has the information you need for any Database link. There is a link on the page for the OpenURL Configuration documentation that talks about what you need to do in the Customization Manager for the OpenURLMapping table. The filed coming into ILLiad as:
determines the request you are going to open. Here are the steps to find out which form will open:
1. You look at the ILLiadAction column for substitute:genre.
2. Then in the OpenURLFieldValues, you will see items as Article, book, etc.
3. If the Genre=article, then you go to the ILLiadValue column and find an entry that looks like Article: Article:ArticleRequest.html. The first entry stands for the Request Type, the second field is Document Type, and the third field is the Web Page that will open.
So if the incoming metadata shows something like rft.genre=article as part of the URL, then the Web Page that will open will be an Article Request. When the request is submitted, the Request type will be Article and the Document Type will be Article.