Just updated a bit,
Now scripts work very fast and goes very smooth even on big projects.
Also I added command Unhide. Before if you hide some objects and wanted unhide them CPlane Labels will unhide too, but with this command all objects will be unhiden except CPlane Labels. So they will stay everytime hidden until you need them.

At 2.18 you load A CPlane Label from your Library

What must I do if I don't use this system of library?
Import an object ? But I have not the axes with it!
Use Transform/Orient Object ?
... I believe I miss something! :)

When You Reset CPlane by Menu, that don't erase the Cplanes Style!
Does this normal?

>>>What must I do if I don't use this system of library?


You can create it by hands, when I have no Custom UI Installed I created simple plans and use them as labels.
You can use for labels any object that you want it can be plane, box or even sphere :)



>>>When You Reset CPlane by Menu, that don't erase the Cplanes Style!
Does this normal?

Yes it how it should be, it is the main idea to keep all labels and CPlane style. It is like repository of CPlanes.

As you can see I create a Star Label but this one stays always on the ground!
even the good CPlane on the Cube is created!
I have not the Star under the mouse!



And if I create the Star on the inclined face of the cube, it stays on this face!
And no Star under the mouse!
I must miss a step! :)

Pilou,
you can move labels only by your hands, it is just an objects with style CPlane that you can reuse to set different CPlanes at the same positions.