About Saved Orientations
Saving an orientation saves the orientation of the view relative to the screen and any pan and zoom orientation associated with the view.
When you save orientations, the display is based on the default orientation of the model. If you change the default orientation of the model (for example, from isometric to trimetric), the orientation of saved orientation changes along with it.
If they are recalled with some of their view orientation references missing, saved orientations retain their orientation but do not retain the history of how that orientation was achieved.