A method for a computer system includes opening a first file describing a first object in an object environment, determining a reference for a second object, wherein the second object includes a plurality of attributes, receiving a second file describing the second object from a storage system; in response to the reference, and opening the second file describing the second object in the object environment, determining a modified value for an attribute from the plurality of attributes for the second object, and including in the first file the reference for the second object and the modified value for the attribute, wherein the second object is not stored in the first file.