Add note about quote pasv

1 files changed, 9 insertions, 3 deletions

diff --git a/2021/prepare.md b/2021/prepare.md
index cad77c69..6cb91c3f 100644
--- a/2021/prepare.md
+++ b/2021/prepare.md
@@ -59,20 +59,26 @@ You can also use a command-line interface with `ftp`:
 ```
 $ ftp ftp-upload.emacsconf.org 21
 > anonymous
+> quote pasv
 > cd upload-here
 > send /local/path/to/file.ext file.ext  # Don't forget the 2nd arg!
 # Ctrl-D to exit
 ```
 
+If you get a `500 Illegal PORT command.` command, make sure to include
+the `quote pasv` part to switch to passive mode before sending your
+file.
+
 If connection fails on the first try, please check to make sure the
 details are exactly as described above; and if the issue persists,
 please email <emacsconf-submit@gnu.org> so we can look into it.
 
 If you have a script or notes for your talk, please include it as well
-so that we could use it to help us with the captioning of your talk.
+so that we could use it to help us with the captioning of your talk. 
 You can also send us additional information to include on the wiki
-page for your talk, such as links to other pages or additional videos.
-If you need help, please email <emacsconf-submit@gnu.org>.
+page for your talk, such as a PDF or links to other pages or
+additional videos.  If you need help, please email
+<emacsconf-submit@gnu.org>.
 
 To record your video, you could use any of the following pieces of
 free software, depending on your needs: