https://www.openbsd.org/mail.html
The typo is in Netiquette, “Plain text” :
« A small number of attachment types are allowed on the mailing lists to support sending patches, shar files, images and small tar or zip files. »
e is missing: shar[e] files.

Would you be kind and help me use the right command
sequence for a diff proposal ?

Here's what I have as per https://www.openbsd.org/anoncvs.html :

 $ pwd                                                                         
/usr
 $ groups                                                                      
sylvain wheel operator wsrc media _gotd got
 $ ls -l                                                                       
total 76
drwxr-xr-x   7 root   wheel   512 Sep 27  2024 X11R6
drwxr-xr-x   2 root   wheel  6144 Apr  6 08:22 bin
drwxr-xr-x   2 root   wheel  1024 Oct 17 08:15 games
drwxr-xr-x  31 root   bin    3072 Oct 17 08:15 include
drwxr-xr-x   6 root   wheel  3584 Apr  6 08:22 lib
drwxr-xr-x   5 root   wheel   512 Oct 17 08:15 libdata
drwxr-xr-x   7 root   wheel  1024 Apr  6 08:22 libexec
drwxr-xr-x  11 root   wheel   512 Sep 27  2024 local
drwxr-xr-x   2 root   wheel   512 Sep 30  2024 mdec
drwxrwx---   2 build  wobj    512 Oct 17 08:14 obj
drwxr-xr-x   2 root   wheel  4096 Apr  6 08:22 sbin
drwxr-xr-x  18 root   wheel   512 Sep 30  2024 share
drwxrwxr-x   2 root   wsrc    512 Oct 17 08:14 src
drwxrwx---   2 build  wobj    512 Oct 17 08:15 xobj
 $ doas mkdir www && doas chgrp wsrc www && doas chmod 775 www 
 $ doas cvs -qd anoncvs@anoncvs.comstyle.com:/cvs checkout -rOPENBSD_7_6 -P www
 $ ls -l
total 76
drwxr-xr-x   7 root   wheel   512 Sep 27  2024 X11R6
drwxr-xr-x   2 root   wheel  6144 Apr  6 08:22 bin
drwxr-xr-x   2 root   wheel  1024 Oct 17 08:15 games
drwxr-xr-x  31 root   bin    3072 Oct 17 08:15 include
drwxr-xr-x   6 root   wheel  3584 Apr  6 08:22 lib
drwxr-xr-x   5 root   wheel   512 Oct 17 08:15 libdata
drwxr-xr-x   7 root   wheel  1024 Apr  6 08:22 libexec
drwxr-xr-x  11 root   wheel   512 Sep 27  2024 local
drwxr-xr-x   2 root   wheel   512 Sep 30  2024 mdec
drwxrwx---   2 build  wobj    512 Oct 17 08:14 obj
drwxr-xr-x   2 root   wheel  4096 Apr  6 08:22 sbin
drwxr-xr-x  18 root   wheel   512 Sep 30  2024 share
drwxrwxr-x   2 root   wsrc    512 Oct 17 08:14 src
drwxrwx---   2 build  wobj    512 Oct 17 08:15 xobj
 $ 

Why no new www folder ? /usr/src is also still enpty.
Before this last attempt I managed to populate the folder 
with Entries, Root, Repository, Tag files, but without 
any html file in sight and not even that any more.

 $ more /home/sylvain/.cvsrc  
# $OpenBSD: dot.cvsrc,v 1.3 2016/10/31 20:50:11 tb Exp $
#
diff -uNp
update -Pd
checkout -P
rdiff -u
 $ 

-- 
Sylvain Saboua
looking for a PDP-11