How i can use it? Diffuse with Opacity

[alividerci]

Diffuse : {BaseTextureName}_D.tga 24bits, RGB (32bits binary alpha if using Opacity)
I dont understand how i can use it, help me anyone pls

[TMarc]

TDOSN

DiffuseOpacity
Specular
Normal

Put your opacity inside diffuse texture in alpha channel you do not need another texture for it and if you are using dds texture than save it as dxt5, if tga than as 32 bits tga with alpha.