diff --git a/README.md b/README.md
index 387e0f8..415c6f4 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,5 @@
 # apple-efi-dump-verbs
+
+This a script to dump codec verbs from some files extracted from Apple
+EFI. GUIDs are `0E8028EB-7594-4EB3-B3C9-13ADAD2EA35A` and
+`124021FC-EE78-45EC-887B-C9A479C8376F`.