Lambert and BlinnPhong

struct SurfaceOutput
{
    fixed3 Albedo;  // diffuse color
    fixed3 Normal;  // tangent space normal, if written
    fixed3 Emission;
    half Specular;  // specular power in 0..1 range
    fixed Gloss;    // specular intensity
    fixed Alpha;    // alpha for transparencies
};

Standard

struct SurfaceOutputStandard
{
    fixed3 Albedo;      // base (diffuse or specular) color
    fixed3 Normal;      // tangent space normal, if written
    half3 Emission;
    half Metallic;      // 0=non-metal, 1=metal
    half Smoothness;    // 0=rough, 1=smooth
    half Occlusion;     // occlusion (default 1)
    fixed Alpha;        // alpha for transparencies
};

Standard Specular

struct SurfaceOutputStandardSpecular
{
    fixed3 Albedo;      // diffuse color
    fixed3 Specular;    // specular color
    fixed3 Normal;      // tangent space normal, if written
    half3 Emission;
    half Smoothness;    // 0=rough, 1=smooth
    half Occlusion;     // occlusion (default 1)
    fixed Alpha;        // alpha for transparencies
};

Vertex/Fragment Structures

AppData

struct appdata_full {
    float4 vertex : POSITION;       //vertex xyz position
    float4 tangent : TANGENT; 
    float3 normal : NORMAL;
    float4 texcoord : TEXCOORD0;    //uv coordinate for first set of UVs
    float4 texcoord1 : TEXCOORD1;   //uv coordinate for second set of UVs
    float4 texcoord2 : TEXCOORD2;   //uv coordinate for third set of UVs
    float4 texcoord3 : TEXCOORD3;   //uv coordinate for fourth set of UVs
    fixed4 color : COLOR;           //per-vertex colour
};
struct v2f
{
    float4 pos :  SV_POSITION;      //The position of the vertex in clipping space.
    float3 normal : NORMAL;         //The normal of the vertex in clipping space.
    float4 uv : TEXCOORD0;          //UV from first UV set.
    float4 textcoord1 : TEXCOORD1;  //UV from second UV set.
    float4 tangent : TANGENT;       //A vector that runs at right angles to a normal.
    float4 diff : COLOR0;           //Diffuse vertex colour.
    float4 spec : COLOR1;           //Specular vertex colour.
}

Multipass Shader Format

Shader "MultipassShader"
{
    Properties    //PROPERTIES BLOCK
    {
        _Color ("Main Color", Color) = (1,1,1,1)
        _MainTex ("Base (RGB)", 2D) = "white" {}
    }
   
    SubShader    //ENCLOSING SHADER BLOCK
    {                            
        //FIRST PASS - SURFACE SHADER DOES NOT REQUIRE PASS BLOCK
        Tags { "Queue" = "Geometry+1" }
 
        CGPROGRAM
        #pragma surface surf BlinnPhong 
       
        float4 _Color;
        struct Input
        {
        };
       
        void surf (Input IN, inout SurfaceOutput o)
        {
        }
        ENDCG
 
        //SECOND PASS - ANOTHER SURFACE SHADER, NO PASS BLOCK REQUIRED
        ZWrite Off      
        Blend DstColor Zero
        CGPROGRAM
        #pragma surface surf BlinnPhong
        float4 _Color;
        struct Input
        {
        };
     
        void surf (Input IN, inout SurfaceOutput o)
        {
        }
        ENDCG  
 
        //THIRD PASS -  VERT/FRAG NEEDS TO BE ENCLOSED IN PASS
        Pass
        {
            Tags { "LightMode" = "Always" }
            ZWrite Off
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #include "UnityCG.cginc"
            sampler2D _MainTex;
         
            struct v2f
            {
            };
            v2f vert (appdata_full v)
            {
            }
                        
            half4 frag( v2f i ) : COLOR
            {
            }
            ENDCG          
        }
       
        //FOURTH PASS - SIMPLE SHADER LAB FUNCTIONS
        Pass
        {          
            Tags { "LightMode" = "Always" }
            ZWrite Off
            SetTexture [_MainTex]
            {
                 combine constant* texture
            }
        } 
    }
    Fallback "Diffuse
 
}