NISO Z39.53 : 0

Foreword
1 Purpose and Scope
  1.1 Purpose
  1.2 Scope
      1.2.1 Usage
      1.2.2 Limitation
2 General Principles of the List
  2.1 Structure of the Language Codes
  2.2 Specificity of the Language Codes
  2.3 Future Development
  2.4 Script
  2.5 Special Language Codes
      2.5.1 Language Code MIS
      2.5.2 Language Code ART
      2.5.3 Language Code MUL
      2.5.4 Language Code UND
3 Structure of the List of Language Codes
  3.1 Descriptors
  3.2 Arrangement of the List of Language Codes
4 Maintenance agency
Tables
Table 1 - List of Language Codes in Alphabetical
          Order by Code
Table 2 - List of Language Codes in Alphabetical
          Order by Descriptor
Table 3 - List of Obsolete Language Codes
Appendix
    Designation of Maintenance Agency

Gives a standardized code for libraries, information services and publishers to indicate language in exchange of information. This standard is not a prescriptive device for the definition of language and dialects but rather a list reflecting the need to distinguish recorded information by language.