Custom Queries are queries that have been configured for you by your system administrator, so that you can quickly and easily select the kinds of documents and folders that you most frequently work with.
Whenever you conduct a Custom Query, its specifications are automatically recorded in a temporary query history, which is maintained for the duration of your current session. At any later time in the same session, you can conduct the same query by clicking Query History on the Home tab, and then selecting the Custom Query from the list in the resulting Query History pane.