Update 1

Major changes

• AACR 2004 update incorporated
• LCRI 2004 Updates 1 & 2 incorporated
• MARC21 2004 Update 4 incorporated
• 13-digit ISBN instructions added
• Typos fixed, especially in examples
• Wording clarified for difficult concepts, based on feedback from workshops

Update 1 - Changed text indicated by a vertical bar in the margin.