- The typical usage is Initialization:>expr.
- Initialization expressions defined in particular cells in a notebook are evaluated when those cells are first made visible, and not necessarily when the notebook is first opened.
- Initialization expressions are guaranteed to be evaluated exactly once before the body of the main function is resolved.
- An object that is already initialized can be initialized again if it is deleted, then restored as a result of using Undo.
Introduced in 2007