This field is used to record the date of material that cannot be entered in 008/06-14. We use it to record one or more Before Common Era (B.C.) dates.
indicators: no indicators, leave blank
punctuation: all subfields end with no punctuation
subfields: $$a - Type of date code (NR)
$$b - Date 1, B.C. date (NR)
$$d - Date 2, B.C. date (NR)
$$e - Date 2, C.E. date (NR)
$$a Type of date code
This subfield is used to enter information similar to that in the 008 byte 06.
i - inclusive dates for a collection. Use this for a group of distinct items, e.g. letters, that are bound together.
s - single known or probable date
m - multiple dates. Use this for a work that is executed over a period of time that can be specified. This would include a manuscript that contains annotations or additions made after its first copying.
q - questionable date. Use this only for a single date that can be narrowed to within a range of years.
$$b Date 1, B.C. date
This subfield is used for a Before Common Era date and entered as 008 bytes 07-10.
$$d Date 2, B.C. date
This subfield is used for a second date that is a Before Common Era date. It is entered as 008 bytes 11-14. This subfield is not used for a single date.
$$e Date 2, C.E. date
This subfield is used for a second date that is a Common Era date. It is entered as 008 bytes 11-14. This subfield is not used for a single date.