An indicator of the quality of a GPS position which takes acount of each satellites location relative to the other satellites in the constellation and their geometry in relation to the GPS receiver A low DOP value indicates a higher probability of accuracy
Directory Operational Binding Management Protocol Specified in the X 500 subspecification ITU-T X 519 (=ISO/IEC 9594-5): " defines the exchange of administrative information between two DSAs to administer operational bindings between them "