The Library of Congress Control Number (LCCN) is a serially based system of numbering cataloging records in the Library of Congress in the United States. It has nothing to do with the contents of any book, and should not be confused with Library of Congress Classification. 

The LCCN numbering system has been in use since 1898, at which time the acronym LCCN originally stood for Library of Congress Card Number. It has also been called the Library of Congress Catalog Card Number, among other names. The Library of Congress prepared cards of bibliographic information for their library catalog and would sell duplicate sets of the cards to other libraries for use in their catalogs. This is known as centralized cataloging. Each set of cards was given a serial number to help identify it. 

Although most of the bibliographic information is now electronically created, stored, and shared with other libraries, there is still a need to identify each unique record, and the LCCN continues to perform that function. 

Librarians all over the world use this unique identifier in the process of cataloging most books which have been published in the United States. It helps them reach the correct cataloging data (known as a cataloging record), which the Library of Congress and third parties make available on the Web and through other media. QUESTIONS:

Q1:
1. What does The Library of Congress Control Number consist of?
2. The Library of Congress Control Number is known as what?
3. 
Q2:
1. Where is the Library of Congress Control Number used?
2. What is the location of the place that uses the Library of Congress Number?
3. 
Q3:
1. What is the Library of Congress Number used to do other than reach the correct cataloging data?
2. What does the Library of Congress Number do other than reach the correct cataloging data?
3. 
Q4:
1. What is the Library of Congress Number used to do other than identify unique records?
2. What does the Library of Congress Number do other than identify unique records?
3. 
Q5:
1. Is the Library of Congress Number now obsolete thanks to electronic cataloging?
2. Has electronic cataloging made the Library of Congress Number obsolete?
3. 
Q6:
1. Is the information contained in the catalog of the Library of Congress made available to people on the outside?
2. Can people on the outside see the information that is contained in the catalog of the Library of Congress?
3. 
Q7:
1. What is one of the names that the Library of Congress' numbering system has other than Library of Congress Catalog Card Number?
2. What is The Library of Congress' numbering system called other than Library of Congress Catalog Card Number?
3. 
Q8:
1. What is one of the names that the Library of Congress' numbering system has other than Library of Congress Card Number?
2. What is The Library of Congress' numbering system called other than Library of Congress Card Number?
3. 
Q9:
1. Why is the term card used in LCCN numbering system of the Library of Congress?
2. Why does the Library of Congress use the term card in the LCCN numbering system?
3. 
Q10:
1. Did the Library of Congress share its cards with other libraries free of charge?
2. Was the sharing of the Library of Congress' cards with other libraries free?
3. 
Q11:
1. What year did the LCCN start being used?
2. The LCCN started being used in what year?
3. 
