For links to data holdings various icons are used to represent services or actions you can take. Those icons are:
		Order the volume (CD-ROM) containing the listed data. The volume will be mailed to you.			The volume (CD-ROM) contains some errors which are documented in an errata log.
		Launch a custom web browser for the resource.			Launch a map based browser for the resource.
		Toggle viewing into brief mode (shorter descriptions are displayed).			Toggle viewing into expanded mode (longer descriptions are displayed).