IV.3. 006

This field provides eighteen character positions (00-17) for coding information about special aspects of the item being cataloged that cannot be coded in field 008 (Fixed-Length Data Elements). It is used in cases when an item has multiple characteristics (e.g., printed material with an accompanying cassette or a map that is issued serially) and to record the coded serial aspects of non-textual continuing resources.  For detailed instructions on how to fill in the data elements, see the MARC 21 documentation.