The GlueX experiment should have a centralized repository where all information regarding the structure and dimensions of the detector and beamline are maintained. This database will be used by Monte Carlo simulations, reconstruction and event displays to define the geometry of the detector. This document contains a proposal defining the way that this information is represented in terms of a single xml document. The document resides in a family of xml files which all follow a common dtd or schema called the Hall D Detector Specification, or HDDS.
