This work is licensed under the Creative Commons Attribution-ShareAlike License. To view a copy of this license, see the file license.txt, visit http://creativecommons.org/licenses/by-sa/2.0 or send a letter to Creative Commons, 559 Nathan Abbott Way, Stanford, California 94305, USA. This component schema defines attribute group declarations for LOM data elements defined in the LOMv1.0 base schema to support schema-based validation of the uniqueness constraints with a LOM XML instance by introducing the attribute "uniqueElementName" for each LOM data element that appears with a multiplicity of at most one. NOTE: For most applications, enforcing the uniqueness constraints using the unique/strict.xsd component XSD is desirable. Although adding the attribute "uniqueElementName" is undesirable, it is unlikely to cause problems. Duplicate declarations are included as comments for completeness. These declarations should remain commented out or they can be removed completely.