renumbering of nodes

Dear all,
I have created a very simple plate geometry to make some exercise on geometry creation. I also read the Mesh module reference and meshed the face later on I tried to renumber the nodes of the mesh both from the python command line tool and from the graphical user interface. But there is no change in the numbering of the nodes on the mesh. I thought that it could be related to the numbering of elements and tried that as well but it also did not change any numbering on my mesh. Can someone comment on this?
Second question is that I guess these numbering operations are conducting/applying the RCM algorithm(or other(s)) on the mesh graph structure, right?
Thanx,
Umut