source: Each entry has a datum (a nugget of data) which is a copy of the datum in some backing store.
target: There is a copy of each datum entry in some backing store.
references: There is a copy of each datum entry in some backing store. Each entry has a copy of data in a backing store. Each entry has a datum and is copied on a back up. Each entry has a datum which is a copy of the datum in some backing store. Each entry has a small bit of data which is a copy of another bit of data. Each entry has a data copy The entry has a small amount of information which is a copy of stored information. Each entry has an information (a nugget of data) which is a copy of the information in some backing store. Each entry has a small piece of information which is a copy of the information in a backup storage. Each entry has a datum (a nugget of data) that is a copy of the datum in back-up storage.