The value of _database_PDB_rev.num must uniquely and
sequentially identify a record in the DATABASE_PDB_REV list.
Note that this item must be a number, and that modification
numbers are assigned in increasing numerical order.
Additional Descriptive Information for Depositors
The value of _database_PDB_rev.num must uniquely
and sequentially identify a record in the _database_PDB_rev
list. Note that this item must be a number, and
that modification numbers are assigned in increasing
numerical order.