[DirectX 8.1 Visual Basic Programmer's Reference] Destination Register Write Masks (100%)

DirectX 8.1 (Visual Basic) > DirectX Graphics > Reference > Pixel Shader Reference > Modifiers

[DirectX October 2006 Documentation] Destination Register Masking (42.3136645962733%)

DirectX Graphics > Direct3D 9 > Reference > Asm Shader Reference > Vertex Shaders > Vertex Shader Registers > Vertex Shader Register Modifiers

[DirectX October 2006 Documentation] Destination Register Write Mask (38.7320592713738%)

DirectX Graphics > Direct3D 9 > Reference > Asm Shader Reference > Pixel Shaders > Registers > Pixel Shader Register Modifiers