In DirectX 11, depth/stencil formats are non-planar so DDS files are as well.
In DirectX 12, depth/stencil formats are planar.
case DXGI_FORMAT_R32G8X24_TYPELESS:
case DXGI_FORMAT_D32_FLOAT_S8X24_UINT:
case DXGI_FORMAT_R32_FLOAT_X8X24_TYPELESS:
case DXGI_FORMAT_X32_TYPELESS_G8X24_UINT:
case DXGI_FORMAT_R24G8_TYPELESS:
case DXGI_FORMAT_D24_UNORM_S8_UINT:
case DXGI_FORMAT_R24_UNORM_X8_TYPELESS:
case DXGI_FORMAT_X24_TYPELESS_G8_UINT:
In DirectX 11, depth/stencil formats are non-planar so DDS files are as well.
In DirectX 12, depth/stencil formats are planar.