These are the "Neckconnector" standard positions used in all TM costume and head meshes.

Meshes indicate which vertexes are closest to these standards, by way of indexes. There is a list, of pairs of mesh vertex index and the closest member's index of this list.

Male heads and costumes:

0 0.070073, 0.000000, 1.543278
1 0.048910, 0.055956, 1.564988
2 0.029399, 0.074874, 1.583479
3 -0.013411, 0.075498, 1.607305
4 -0.043935, 0.043576, 1.611162
5 -0.048926, 0.000001, 1.607596
6 -0.043935, -0.043576, 1.611162
7 -0.013411, -0.075498, 1.607305
8 0.029399, -0.074873, 1.583479
9 0.048910, -0.055956, 1.564988

Female heads and costumes

0 0.074359, 0.000005, 1.549346
1 0.049324, 0.049710, 1.573448
2 0.028644, 0.064228, 1.590175
3 -0.016194, 0.055339, 1.601248
4 -0.038122, 0.034884, 1.601856
5 -0.048233, -0.000011, 1.601135
6 -0.038122, -0.034884, 1.601855
7 -0.016193, -0.055339, 1.601248
8 0.028644, -0.064228, 1.590175
9 0.049324, -0.049706, 1.573445