VK_FORMAT_B12X4G12X4R12X4G12X4_422_UNORM_4PACK16_KHR

Undocumented in source but is binding to an external library. You might be able to learn more by searching the web for its name.
@nogc nothrow extern (System)
enum VK_FORMAT_B12X4G12X4R12X4G12X4_422_UNORM_4PACK16_KHR = VkFormat.VK_FORMAT_B12X4G12X4R12X4G12X4_422_UNORM_4PACK16_KHR;

Meta