First, just what do you mean by "make file"? You refer to cmake, make, and .mk in three places in your message. How about a link to the actual tool you're interested in? And a brief list of the other tools you're
using it with.
Is this it?
http://www.cmake.org/
Once we're talking about the same tool, then the question is what "elements" are you interested in? If your cmake is anything like the traditional make program, the format is deceptively simple, and enormously complex in usage.
But I suspect that your cmake has very little to do with Unix make tools. The cmake that I gave the link for uses a CMakeLists file, which looks nothing like a makefile.