This is hasty response Thomas Clay Templeton's interesting note about the
topic named in the subject line. We at LC have been chewing on this for
several months, and have concocted a diagram in which we sketch some of
our thoughts. Morgan Cundiff has presented it in some of his talks, for
example in slides 9 and 10 at this URL:
Morgan may chime in with some additional thoughts. We all need to keep
talking about this in order to get it right!
Library of Congress