066 field:

In the MARC format, field 066 contains information specifying the character sets present in the record. The field alerts users that special processing may be required. It is often used in conjunction with field 880 (Alternate Graphic Representation) in MARC records.

For more information, select:

066 Character Sets Present (Authority)

066 Character Sets Present (Bibliographic)

066 Character Sets Present (Classification)

066 Character Sets Present (Community Information)

066 Character Sets Present (Holdings)