diff --git a/asterix-doc/src/site/markdown/csv.md b/asterix-doc/src/site/markdown/csv.md
index 8e056b4..338aa55 100644
--- a/asterix-doc/src/site/markdown/csv.md
+++ b/asterix-doc/src/site/markdown/csv.md
@@ -77,8 +77,11 @@
 AsterixDB operation, as AsterixDB's CSV output always has a header
 line.
 
-CSV data may also be loaded from HDFS; see
-[Accessing External Data](aql/externaldata.html) for details.
+CSV data may also be loaded from HDFS; see [Accessing External
+Data](aql/externaldata.html) for details.  However please note that
+CSV files on HDFS cannot have headers; attempting to specify
+"header"="true" when reading from HDFS could result in non-header
+lines of data being skipped as well.
 
 ## CSV Output