//!
//! Basically, the system provides the following categories :
//! Shape (Geometry, BRep, CSG, Features, etc...)
-//! Drawing (Drawing, Views, Annotations, Pictures, Scketches ...)
+//! Drawing (Drawing, Views, Annotations, Pictures, Sketches ...)
//! Structure (Component & Part, Groups & Patterns ...)
//! Description (Meta-Data : Relations, Properties, Product ...)
//! Auxiliary (those which do not enter in the above list)