diff --git a/youtube_dl/options.py b/youtube_dl/options.py
index 7d1bbc021..529a989dc 100644
--- a/youtube_dl/options.py
+++ b/youtube_dl/options.py
@@ -676,7 +676,7 @@ def parseOpts(overrideArguments=None):
     filesystem.add_option(
         '-a', '--batch-file',
         dest='batchfile', metavar='FILE',
-        help='File containing URLs to download (\'-\' for stdin)')
+        help='File containing URLs to download (\'-\' for stdin). Lines starting with \'#\' are comments.')
     filesystem.add_option(
         '--id', default=False,
         action='store_true', dest='useid', help='Use only video ID in file name')