Default Vertex and Pixel Shader Inputs

If you're just opting for default Vertex and Pixel inputs which are usable on the default shading model, these are the reference member variables for each:

struct VertexInput
{
    float3 vPositionOs : POSITION < Semantic( PosXyz ); >;
    float2 vTexCoord : TEXCOORD0 < Semantic( LowPrecisionUv ); >;	
    float2 vTexCoord2 : TEXCOORD1 < Semantic( LowPrecisionUv1 ); >;	
    float4 vNormalOs : NORMAL < Semantic( OptionallyCompressedTangentFrame ); >;

    #if ( VS_INPUT_HAS_TANGENT_BASIS )
    	float4 vTangentUOs_flTangentVSign : TANGENT	< Semantic( TangentU_SignV ); >;
    #endif
    
    //-------------------------------------------------------------------------------------------------------------------------------------------------------------
    // SSS Curvature
    //-------------------------------------------------------------------------------------------------------------------------------------------------------------
    #if ( S_USE_PER_VERTEX_CURVATURE )
    	float flSSSCurvature : TEXCOORD2 < Semantic( Curvature ); >;
    #endif
    
    //-------------------------------------------------------------------------------------------------------------------------------------------------------------
    // Compute Skinning
    //-------------------------------------------------------------------------------------------------------------------------------------------------------------
    #if ( D_CS_VERTEX_ANIMATION )
    	float4 vBlendWeight : BLENDWEIGHT 	< Semantic( BlendWeight ); >;

    	float nVertexIndex : TEXCOORD14 < Semantic( MorphIndex ); >;
    	float nVertexCacheIndex : TEXCOORD15 < Semantic( MorphIndex ); >;
    #endif
    
    //-------------------------------------------------------------------------------------------------------------------------------------------------------------
    // Instancing data
    //-------------------------------------------------------------------------------------------------------------------------------------------------------------
    uint nInstanceTransformID : TEXCOORD13 < Semantic( InstanceTransformUv ); >;
    uint nBoneIndex 		  : BLENDINDICES < Semantic( BlendIndices ); >; // 1D Blend Index for rigid objects transforms, skinning_cs takes uint4 from mesh
    
    //-------------------------------------------------------------------------------------------------------------------------------------------------------------
    // Baked lighting
    //-------------------------------------------------------------------------------------------------------------------------------------------------------------
    #if ( D_BAKED_LIGHTING_FROM_LIGHTMAP )	
    	float2 vLightmapUV : TEXCOORD3 < Semantic( LightmapUV ); > ;
    #endif
}

struct PixelInput
{
    #if ( PROGRAM == VFX_PROGRAM_PS )
    	float3 vPositionWithOffsetWs : TEXCOORD0;
    #else
    	float3 vPositionWs : TEXCOORD0;
    #endif
    
    float3 vNormalWs 		: TEXCOORD1;
    float4 vTextureCoords 	: TEXCOORD2;
    float4 vVertexColor 	: TEXCOORD4;

    #if ( PS_INPUT_HAS_TANGENT_BASIS )
		float3 vTangentUWs : TEXCOORD6; 
        float3 vTangentVWs : TEXCOORD7; 
    #endif

    #if ( S_USE_PER_VERTEX_CURVATURE )
    	float flSSSCurvature : TEXCOORD11;
    #endif

    centroid float2 vLightmapUV : TEXCOORD3;

    //-------------------------------------------------------------------------------------------------------------------------------------------------------------
    // System interpolants
    //-------------------------------------------------------------------------------------------------------------------------------------------------------------

    #if ( PROGRAM != VFX_PROGRAM_PS ) 
    	float4 vPositionPs : SV_Position;
    #else // PS only
    	float4 vPositionSs : SV_Position;
    	#if ( S_RENDER_BACKFACES )
    		bool face : SV_IsFrontFace;
    	#endif
    #endif
}

Different combos expose different feature sets for these