863-865 $p - Piece designation:

Subfield $p contains an identification of a piece. The designation may be an identification number such as a bar code number or an accession number.

The piece designation may be preceded by an uppercase B or U specify whether the piece is bound or unbound. When no piece designation exists, a double dash (//) may be recorded in subfield $p to signify that the holdings relate to a piece.

When the piece designation applies to the entire holdings statement, it is recorded in subfield $p (Piece designation) of field 852 (Location) . When the piece designation apples to the enumeration and chronology recorded in field 863-865 it is recorded there. When the piece designation applies only at the item level, it is recorded in subfield $p of the item information field 876-878. Example: