diff --git a/src/win32_init.c b/src/win32_init.c
index e00baff4..adb87b60 100644
--- a/src/win32_init.c
+++ b/src/win32_init.c
@@ -35,15 +35,15 @@ DEFINE_GUID(GUID_DEVINTERFACE_HID,0x4d1e55b2,0xf16f,0x11cf,0x88,0xcb,0x00,0x11,0
 
 #if defined(_GLFW_USE_HYBRID_HPG) || defined(_GLFW_USE_OPTIMUS_HPG)
 
-// Applications exporting this symbol with this value will be automatically
-// directed to the high-performance GPU on Nvidia Optimus systems with
-// up-to-date drivers
+// Executables (but not DLLs) exporting this symbol with this value will be
+// automatically directed to the high-performance GPU on Nvidia Optimus systems
+// with up-to-date drivers
 //
 __declspec(dllexport) DWORD NvOptimusEnablement = 1;
 
-// Applications exporting this symbol with this value will be automatically
-// directed to the high-performance GPU on AMD PowerXpress systems with
-// up-to-date drivers
+// Executables (but not DLLs) exporting this symbol with this value will be
+// automatically directed to the high-performance GPU on AMD PowerXpress systems
+// with up-to-date drivers
 //
 __declspec(dllexport) int AmdPowerXpressRequestHighPerformance = 1;
 
diff --git a/src/x11_window.c b/src/x11_window.c
index 487098a2..db34e9d9 100644
--- a/src/x11_window.c
+++ b/src/x11_window.c
@@ -2428,6 +2428,8 @@ void _glfwPlatformGetRequiredInstanceExtensions(char** extensions)
 
     extensions[0] = "VK_KHR_surface";
 
+    // NOTE: VK_KHR_xcb_surface is preferred due to some early ICDs exposing but
+    //       not correctly implementing VK_KHR_xlib_surface
     if (_glfw.vk.KHR_xcb_surface && _glfw.x11.x11xcb.handle)
         extensions[1] = "VK_KHR_xcb_surface";
     else