852 $z - Public note:

Subfield $z contains a note relating to the location of the item identified in the field. The note is written in a form that is adequate for public display. A note not for public display is contained in subfield $x (Nonpublic note).

A public note that applies to a specific part of the holdings is contained in subfield $z (Public note) of the 863-865 Enumeration and Chronology field relating to the part. Example: