The purpose of a WBS dictionary is to provide:
A.
additional details for each component of the WBS, and for each component provide a brief definition of its statement of work, outputs, actual activities and pertinent milestones.
B.
a detailed glossary of terms used in the WBS.
C.
written authorization to sanction work on a particular work-package within the WBS, and define the methods for its implementation and the monitoring of its performance.
D.
a hierarchical decomposition of the work to be undertaken to address the objectives and meet the requirements of the project at the lowest level.