L1/L2/L3 Levels Difference / Criaterias

Hi,

I was wondering that what are the Linux System Administrator Different Levels mentioned in Jobs profiles.
L1/L2/L3/?4 etc.

What are the basic functionality Difference in different levels or what are the different role of administrater in different Layers.

Any related help/ Tach Link will be helpful to grasp the information.
Thanks in advance.

Is this what you're looking for?

http://www.cyberciti.biz/faq/what-is...support-level/

Yeah , That's right. The same I was searching; but with little more detailed knowledge. But any way thaks for the same. If you have any more link pl reffer it.

Thanks