Update runtime files.
diff --git a/runtime/doc/channel.txt b/runtime/doc/channel.txt
index fd08cd4..cb6f781 100644
--- a/runtime/doc/channel.txt
+++ b/runtime/doc/channel.txt
@@ -1,4 +1,4 @@
-*channel.txt* For Vim version 8.1. Last change: 2018 Apr 18
+*channel.txt* For Vim version 8.1. Last change: 2019 Mar 21
VIM REFERENCE MANUAL by Bram Moolenaar
@@ -308,9 +308,10 @@
Command "redraw" ~
-The other commands do not update the screen, so that you can send a sequence
-of commands without the cursor moving around. You must end with the "redraw"
-command to show any changed text and show the cursor where it belongs.
+The other commands do not explicitly update the screen, so that you can send a
+sequence of commands without the cursor moving around. A redraw can happen as
+a side effect of some commands. You must end with the "redraw" command to
+show any changed text and show the cursor where it belongs.
The argument is normally an empty string:
["redraw", ""] ~