This Informational Report describes the theoretical aspects of and discusses trade-offs and system performance for the navigation technique known as Delta Differential One-Way Ranging (Delta-DOR). The topics covered include a general description of the technique, theoretical background, definition of observables, estimates of system performance, system trade-offs, and descriptions of existing systems. This Report deals explicitly with the technical definitions and conventions associated with inter-Agency cross-support situations involving Delta Differential One-way Ranging operations.