Component location in a .vho netlist written with EDA tools

Hello,

I generated a .vho netlist with EDA tools and I try to find information about signal locations. For example in this netlist I found in comment :

-- Location: MLABCELL_X104_Y57_N48

So in parallel with Chip Planner, I am ok that my signal has coordinate (104 , 57) but I don't know what does N48 mean. Any idea ? Does it refer to an element in the MLABCELL ?

And in this netlist, the coordinate system is a global one or is there other coordinate systems for specific logic blocks in Altera place-and-route methods ?

Thanks