sentences:  CD-R is a successful technology that has proven its reliability over period of time, but it should be viewed with caution for long term storage as the media is easily scratched.The safest way is to make a "gold master" CD that is not ever checked out for use from the library, and duplicate copies of this for use by people wishing to access it.The Folk Heritage Collections, at the Library of Congress, set a standard for 24 bits when digitizing music.