I am developing a FEM code, and in this case I am trying to define everything in the mesh file, I mean: domains, boundaries, properties of domains, etc, everything that involves problem settings. See the following *.geo file:

Point(1) = {0, 0, 0, 1.0}; Point(2) = {1, 0, 0, 1.0}; Point(3) = {1, 1, 0, 1.0}; Point(4) = {0, 1, 0, 1.0}; Point(5) = {0, 0.5, 0, 1.0}; Point(6) = {1, 0.5, 0, 1.0}; Line(1) = {1, 2}; Line(2) = {2, 6}; Line(3) = {6, 3}; Line(4) = {3, 4}; Line(5) = {4, 5}; Line(6) = {5, 1}; Line(7) = {5, 6}; Line Loop(8) = {4, 5, 7, 3}; Plane Surface(9) = {8}; Line Loop(10) = {7, -2, -1, -6}; Plane Surface(11) = {10}; Physical Surface('top') = {9}; Physical Surface('bottom') = {11};

I am moving forward tryinig to understand if it is possible to give each domain characteristics to the physical entities defined in the *.geo file. It is my intention to write in the *.geo file the aforementioned definitions. Is this possible to do?