Links have been provided to GS1 pages on GTIN8, GTIN13 and GTIN14 in Offer and Product. It would be helpful as well to add links to GS1 information on the Global Location Number in the Organization class. These are the links to the GS1 Global Data Dictionary definition for GLN as well as the GS1 GLN Summary:

http://apps.gs1.org/GDD/glossary/Pages/Global%20Location%20Number%20(GLN).aspx
http://www.gs1.org/barcodes/technical/idkeys/gln