diff --git a/README.md b/README.md
index 0643c94a52..d0672f6362 100644
--- a/README.md
+++ b/README.md
@@ -27,3 +27,5 @@ AIR             |                    |       |
 DXIR            |                    |       |
 DXIL            |                    |       |
 DXBC            |                    |       |
+
+:heavy_check_mark: = Primary support — :white_check_mark: = Secondary support — :construction: = Unsupported, but support in progress