Assigning Materials to Textures (Bumpmapping)

Ok, real quick question:

How does TSE figure out which texture is the normal map assigned to a certain texture, etc?

In MaterialMap.cs I see this:

//---------------------------------------------------------------------------
// Interior materials
//---------------------------------------------------------------------------
//Alex's Textures
addMaterialMapping("wall_light", "material: wall_light");
addMaterialMapping("plating", "material: plating");
addMaterialMapping("t2plate", "material: t2plate");
addMaterialMapping("solidmetal", "material: solidmetal");
addMaterialMapping("solidrust", "material: solidrust");
addMaterialMapping("concrete", "material: concrete");
addMaterialMapping("ggsolidmetal", "material: ggsolidmetal");
addMaterialMapping("solidmetal_lights", "material: solidmetal_lights");
addMaterialMapping("metalgrate", "material: metalgrate");
addMaterialMapping("wall", "material: wall");
addMaterialMapping("wall_flat", "material: wall_flat");
addMaterialMapping("aquagrad", "material: aquagrad");
addMaterialMapping("corridor_trim", "material: corridor_trim");

Now after looking in /interiors/test/ I see textures with the same names, i.e. wall_light.png with a wall_light_bump.png and so forth.
Does TSE assume that the texture with an extension "_bump" is the normal map? So say I create mytexture.png as my texture and create a normal map and save it as mytexture_bump.png and add the material mapping addMaterialMapping("mytexture", "material: mytexture"); ...then will TSE assume that mytexture_bump.png is the normal map? It looks like it's referring to a list of materials in the materialmapping ("material: wall_light") for example, but I can't find that list of materials...any ideas? I'm assuming maybe that's where these things such as normal maps or glow maps are defined?