diff --git a/README.md b/README.md
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--- a/README.md
+++ b/README.md
@@ -1,2 +1,5 @@
 # anzsic codes
 ANZSIC codes in a standard table format for people who are sick of ABS for sharing data in non-standard formats.
+
+# Known issues
+Please note that the 'nfd' (not further defined) classes are missing from the anzsic tables, as repoted by @baslat in https://github.com/asiripanich/anzsic/issues/1. PRs to fix are welcome.