Jorgen
If two different GMT files contain the same material name but with different definitions, which definition will actually be used? The one that loads first, the one that loads last, or is it undefined?
Luc Van Camp
The one that gets loaded first, because from an optimization point of view, it's better to skip a material that's already been loaded to memory. If it had been the other way, it would mean that the game could possibly attempt to load the same material 1000 times (this obviously takes time) and only keep one of them. That just wouldn't be logical 
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.Jorgen
Makes perfect sense, thanks Luc!