It is assumed that the reader of this document has some background knowledge of the programming environment being used (e.g. see SUN/101 & SG/4 for details of ADAM) and with the basic concepts used by the HDS data system (SUN/92).
A knowledge of the method by which the NDF is implemented using HDS (SGP/38) may also be useful as background reading, but is not essential for understanding the present document which is intended to be self-contained in its description of NDF concepts and facilities.