Missing texture in Content Example

I am following the Landscape Quick Start Guide

But in the ExampleContent/Landscapes/Textures/, I cannot find these textures:

T_LS_Grass_01_D
T_LS_Grass_01_N
T_FullGrass_D
T_FullGrass_N
T_IceNoise_N

I see some textures have VT mark, what is that mean?