diff --git a/doc/DESCRIPTION.md b/doc/DESCRIPTION.md
index b6fee80..6dc3f46 100644
--- a/doc/DESCRIPTION.md
+++ b/doc/DESCRIPTION.md
@@ -1,3 +1,3 @@
-Offer backup storage to a friend.
+Setup a storage space to be used for backup using Borg
 
-The main goal of Borg is to provide an efficient and secure way to backup data. The data deduplication technique used makes Borg suitable for daily backups since only changes are stored. The authenticated encryption technique makes it suitable for backups to not fully trusted targets.
+This app is the "server" part, meant to be installed on the machine providing the backup storage. It is designed to work in combination with the [borg 'client' app](https://apps.yunohost.org/app/borg) installed on a diffent machine.
diff --git a/doc/PRE_INSTALL.md b/doc/PRE_INSTALL.md
new file mode 100644
index 0000000..e6c47bd
--- /dev/null
+++ b/doc/PRE_INSTALL.md
@@ -0,0 +1 @@
+Note that you should *first* install the other app (`borg_ynh`) on the other machine, and *then* this app (`borgserver_ynh`). After the install of the 'client' app (`borg_ynh`), your friend will be provided with the info, in particular the SSH public key, to be used for this app's installation.