AFAIK, Google accepts sitemaps which are about ordinary URLs (text/plain), images (image/png, image/gif, image/jpg, etc.), and videos (video/avi, video/mpeg, etc.).
My question is, how many Internet Media Types (formerly known as MIME Types) can have sitemaps. For example, if I'm a researcher, can I create a sitemap for my PDF files (application/pdf), or can a compose create a sitemap for his/her compositions (audio/mpeg3)?