Is it possible to rotate coordinate system instead of object?

Hi all,
I would like to rotate my coordinate system depending on the orientation of a marker that i scan once at the start of my application. Is it possible to rotate the main cameras coordinate system? With rotation I mean the rotation of the axes. E.g. that the x axis of the old coordinate system is now the z axis.
If that is not possible there could be another solution:
When the app has detected the marker it will place an object on that marker. Depending on how to the marker is oriented the object will be placed with some rotation with respect to the main cams coord system.
Now is it possible to place that object with a different coord system rather than with rotation?
Hope for answers and thanks!

Good day.

You can not change Unity global axis (i think). But what you can do is a very simple solution. Make all the objects of the scene child of one general Empty Object. This way you can rotate this general empty object, so all cameras and everything will rotate. Its general rotation will change, but LocalRotation (relative to this general empty object) will not.

Bye!