X53 Scheme-Specific Conventions: Library of Congress Classification

Classification Number Elements: A classification number from the Library of Congress Classification scheme is divided into the following elements:

subclass letter(s)

digit portion before the point

digit portion after the point

alphanumeric (Cutter) portion

date portion

other data portion

Each element appearing in a classification number is recorded in a separate subfield to facilitate correct sorting and to enable a system to suppress a portion of the number for display purposes. If there is more than one occurrence of an element type in a classification number (e.g., Cutter portion, date portion), each occurrence is recorded in a separate subfield.

Order of Subfields: The elements of a classification number are recorded in subfields in the order they appear in the classification number. In recording a span of numbers, all elements of the beginning number of the span are recorded in one set of subfields $a, followed by all elements of the ending number of the span recorded in one set of subfields $c. Note that all elements of the ending number of the span are to be recorded, even if they duplicate elements recorded for the beginning number of the span.

Punctuation: The point used to separate digit portions of a classification number is recorded in the subfield for the digit portion following the point. The point used to separate the digit portion from the first alphanumeric portion of a classification number is recorded in the subfield for the first alphanumeric portion. Generally, punctuation (commas, periods, dashes, etc.) occurring within the caption are included in recording the caption in both subfields $h (Caption hierarchy) and $j (Caption).

Subarrangement Sequence Numbers: For a table that designates numbers by sequencing rather than the actual classification number, the sequence number is enclosed in square brackets. For example:

153 ##$yZ$z1$a[10]$jBiobibliography

where [10] stands for the tenth in a sequence of classification numbers.

For a table that designates captions for a sequence of alphanumeric numbers using the letter x to stand for the basic alphanumeric part, the notation as presented in the table is recorded in separate subfields as appropriate.

153 ##$yP$z44$a.x2$aA4$hBiography and criticism$jLetters (Collections)

Table Numbers: Table numbers should be input as arabic numerals. If desired, roman numerals may be generated upon display.

See also:

Scheme-Specific Conventions: Dewey Decimal Classification

For return, select:

X53 Classification Numbers - General Information