Shelf-Reading: Library Of Congress

## FIRST LINE

The first line will have from one to three letters, and indicates order alphabetically, the same way as a dictionary. For example:

 A AA AB AC AD AE AF AG AH AJ AK ….. AZ

Not all the letters will be used. These examples are to give you a rough idea of how the system works. Here is an example of the first line with three call numbers.

 KFA KFB KFC KFD …… KFX

## SECOND LINE

Next, when the first line of the call number is identical, then the second line is used to determine order numerically. The second line is a whole number.
For example:

 PS PS PS 65 585 3515

(The second line of the call number PS 65 is read as sixty-five.)
(The second line of the call number PS 585 is read as five hundred, eighty-five.)
(The second line of the call number PS 3515 is read as three thousand, five hundred and fifteen.)

## SECOND LINE WITH A DECIMAL

Sometimes, the second line which is a whole number is followed by a decimal. The whole number comes first, followed by the decimals, which go in order from smallest to largest. You must match the decimal number-for-number making sure the smallest numbers go first.

 PS PS PS 3515.115 3515.12 3515.5

These books would go on the shelf after any books with the PS 3515 call number.

## THIRD LINE

If the first two lines are identical, then you should go to the third line to determine call number order. The third line ALWAYS begins with a decimal point followed by a letter, and then one or more digits. Like the previous example, the numbers go from the smallest to the largest, matching number-for-number.
Look at the following example:

 PS PS PS PS PS PS 3515 3515 3515 3515 3515 3515 .M112 .M12 .M135 .M2 .M213 .M23

With this example, it would appear at first that "2" should come before "112." However, if you compare the first digit after the M, “1" comes before “2", so this determines the order. Remember, the third line is NOT read as a whole number!

## FOURTH LINE

The fourth line is a continuation of the third line. It should be read alphabetically, and then as a decimal. If the first three lines of the call number are the same, then you must go to the forth line.
For example:

 PS PS 3515 3515 .R3457 .R3457 U137 U17

It would appear at first that "17" should come before "137." The first digits after the U, “1” is the same for both yet the next digit “3” is before “7,” so this determines the order. Remember, the fourth line is NOT read as a whole number!

## NOTHING COMES BEFORE SOMETHING RULE:

The call number with less information goes before the one with more.
For example:

 PS PS 3515 3515 .R3457 .R3457 2006 U137 2003

Another Example:
If two call numbers are the same, except that one has an additional line beyond the other, the call number with more information is considered to be higher.
For example:

 PS PS 3515 3515 .R3457 .R3457 U137 U137 2006

## OTHER ODDITIES:

If you see a call number with the third line that looks like a zero, it is really the letter O. Example, PS 3515 .O17
If you see a call number with the third line that looks like a one, it is really the letter I. Example, PS 3515 .l17

procedure manual

page revision: 46, last edited: 20 Nov 2013 19:39
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