California Digital Library Index Data ApS The HTTP URL Mapping Protocol (THUMP) is a set of URL-based conventions for retrieving information and conducting searches. THUMP can be used for focused retrievals or for broad database queries. A THUMP request is a URL containing a query string that starts with a `?', and can contain one or more THUMP commands. Returned records are formatted with Dublin Core Kernel metadata as Electronic Resource Citations, which are similar to blocks of email headers.