Embedded holdings information:

When holdings information is embedded in a MARC bibliographic record, multiple 852 fields may be used only when the information does not include other holdings information fields that must be linked to a specific 852 field for intelligibility.  When field linking is required, one 852 field and the other fields associated with it may be embedded in the bibliographic record.  Separate holdings records must be made for each of the other 852 fields and its associated fields.