Next: MMDSL: a Multi-Mission Data Server at LAEFF . ... Laboratoire des Sciences de l'Image, de l'Informatique et de la T?l?detection, France . ... We present an example implementation of a data tree in the Astrophysical Virtual Observatory prototype tool. ... Here we provide a very brief outline of the image metadata description that forms the basis of this data access scheme, and show how the data tree is used in the AVO prototype to enable ``smart browsing'' and selection of data. ...