852 $g - Non-coded location qualifier:

Subfield $g contains a textual description that identifies the specific units of an item that are housed in a location different from that of the main holdings of the same item when the location qualifier cannot be expressed in coded form is subfield $f (Coded location qualifier).

Subfield $g contains a non-coded location qualifier, not retention information. Retention information is coded in field 008/12 (General retention policy) and 008/13-15 (Specific retention policy). Example: