diff --git a/youtube_dl/YoutubeDL.py b/youtube_dl/YoutubeDL.py
index 29d8517a3..442aa663b 100755
--- a/youtube_dl/YoutubeDL.py
+++ b/youtube_dl/YoutubeDL.py
@@ -131,9 +131,9 @@ class YoutubeDL(object):
     username:          Username for authentication purposes.
     password:          Password for authentication purposes.
     videopassword:     Password for accessing a video.
-    ap_mso:            Adobe Pass Multiple-system operator Identifier.
-    ap_username:       TV Provider username for authentication purposes.
-    ap_password:       TV Provider password for authentication purposes.
+    ap_mso:            Adobe Pass multiple-system operator identifier.
+    ap_username:       Multiple-system operator account username.
+    ap_password:       Multiple-system operator account password.
     usenetrc:          Use netrc for authentication instead.
     verbose:           Print additional info to stdout.
     quiet:             Do not print messages to stdout.