Study - Library of Congress...thank God for USA

LOC made simple:

Example: BS 123 . A456 v.2 1990

BS Alphabetical A, AB, ABC, B, BA, BB, C, etc

123 Whole number 1, 2, 3, etc

. A 456 Alphabetical A, AB, ABC, B, BA, BB, C, etc
Decimal number following the letter is a decimal ex: .1222, .2, .23,

V. 2 Volume...numerical/alphabetical order V. 1, V. 2, etc

1990 Chronological year 1990, 1991, 1992, etc.

Stacks are read 'left to right; top of a bookcase to bottom'.

When all else fails, just ask; 'we live for this stuff'.