The Library of Congress Classification schedules have
traditionally used parentheses around certain class numbers to
indicate one of two conditions: (1) the number was formerly valid
but is now obsolete and no longer used by LC, or (2) the number is
an optional number that was never used by LC but is provided for
those libraries that wish to follow an arrangement that differs from
LC practice. In either case, a see reference or explanatory note generally
appears at the location of the parenthesized number to
indicate to the user the valid number currently used by LC.
CPSO has introduced a change in the display conventions for
these two types of numbers. Numbers of the first type continue
to be displayed in parentheses, but numbers of the second type are
now displayed in angle brackets. See references or explanatory notes
continue to appear under both types of numbers. This change in displays
has already been implemented in LCC Online (Minaret) and Classification
Web. It will also appear in new printed editions of the classification
schedules dated 2003 or later.
Examples of numbers that were formerly parenthesized but now
appear in angle brackets are at JZ5528 , KF175, and PS8001-8599.