# HLSL semantics reference

> Reference for supported High-Level Shader Language (HLSL) semantics in Unity.

Explore the semantics you can use to input mesh data into custom shaders in High-Level Shader Language (HLSL) in Unity.

| **Semantic**  | **Description**                                                                     | **Type**                                                                                     |
| ------------- | ----------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------- |
| `POSITION`    | The vertex position.                                                                | `float3` or `float4`                                                                         |
| `NORMAL`      | The vertex normal.                                                                  | `float3`                                                                                     |
| `TEXCOORD0`   | The first UV coordinates.                                                           | `float2`, `float3`, or `float4`                                                              |
| `TEXCOORD1`   | The second UV coordinates.                                                          | `float2`, `float3`, or `float4`                                                              |
| `TEXCOORD2`   | The third UV coordinates.                                                           | `float2`, `float3`, or `float4`                                                              |
| `TEXCOORD3`   | The fourth UV coordinates.                                                          | `float2`, `float3`, or `float4`                                                              |
| `TANGENT`     | The tangent vector used for normal mapping.                                         | `float4`                                                                                     |
| `COLOR`       | The per-vertex color.                                                               | `float4`                                                                                     |
| `VPOS`        | The pixel position in screen space. You can use `VPOS` only in the fragment shader. | Use `UNITY_VPOS_TYPE` for cross-platform compatibility, which is `float4` on most platforms. |
| `VFACE`       | Indicates whether the pixel surface is facing the camera.                           | `float`                                                                                      |
| `SV_VertexID` | The index of the vertex. You can't use `SV_VertexID` in Surface Shaders.            | `uint`                                                                                       |

## Additional resources

* [HLSL pragma directives reference](/engine/6000.0/manual/materials-and-shaders/shaders/reference/sl-pragma-directives.md)
* [Semantics](https://learn.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-semantics) in the Microsoft HLSL documentation