diff --git a/data/avro/README.md b/data/avro/README.md
index 2707e12..f6c48e2 100644
--- a/data/avro/README.md
+++ b/data/avro/README.md
@@ -35,3 +35,9 @@
     }
 }
 ```
+
+Additional notes:
+
+| File  | Description   |
+|:--|:--|
+| alltypes_nulls_plain.avro   | Contains a single row with null values for each scalar data type, i.e, `{"string_col":null,"int_col":null,"bool_col":null,"bigint_col":null,"float_col":null,"double_col":null,"bytes_col":null}`. Generated from https://gist.github.com/nenorbot/5a92e24f8f3615488f75e2a18a105c76   |