diff --git a/mx-linux/mx-21.sh b/mx-linux/mx-21.sh
index 55273e1..84b991b 100644
--- a/mx-linux/mx-21.sh
+++ b/mx-linux/mx-21.sh
@@ -35,18 +35,24 @@ echo 'deb [arch=amd64 signed-by=/usr/share/keyrings/signal-desktop-keyring.gpg]
   sudo tee -a /etc/apt/sources.list.d/signal-xenial.list
 apt-get update $1
 apt-get upgrade $1
+# mkusb from ppa
 apt-get install $1 mkusb
-#python 3.9.2 already installed in MX21
-#<-- cpupower
+# python 3.9.2 already installed in MX21
+#<-- cpupower from ppa
 apt-get install $1 cpupower-gui
 apt-get install $1 gir1.2-handy-1
 #--> cpupower
 apt-get install $1 net-tools
+# telegram from ppa
 apt-get install $1 telegram
+# signal from ppa
 apt-get install $1 signal-desktop
 apt-get install $1 veracrypt
+# truecrypt from ppa
 apt-get install $1 truecrypt
+# cryptomator from ppa
 apt-get install $1 cryptomator
+# eddie from ppa
 apt-get install $1 eddie-ui
 apt-get install $1 flameshot
 apt-get install $1 -t buster-backports inkscape
@@ -56,6 +62,7 @@ apt-get install $1 virtualbox virtualbox-dkms virtualbox-ext-pack virtualbox-gue
 apt-get install $1 python3-pip
 pip3 install numpy
 pip3 install notebook
+# brave from ppa
 apt-get install $1 brave-browser
 #3d mouse
 wget http://ftp.pl.debian.org/debian/pool/main/s/spacenavd/spacenavd_0.7.1-1_amd64.deb
@@ -72,7 +79,7 @@ sudo ./install.sh
 # run /opt/turtl/turtl
 # download vmwareplayer: https://my.vmware.com/en/web/vmware/downloads/details?downloadGroup=WKST-PLAYER-1612&productId=1039#product_downloads
 ./VMware-Player-16.1.2-17966106.x86_64.bundle
-#ecryptfs not available in current repo -> direct download
+# ecryptfs not available in current repo -> direct download
 wget http://ftp.de.debian.org/debian/pool/main/e/ecryptfs-utils/ecryptfs-utils_111-5_amd64.deb
 wget http://ftp.de.debian.org/debian/pool/main/e/ecryptfs-utils/libecryptfs1_111-5_amd64.deb
 apt-get install $1 ./ecryptfs-utils_111-5_amd64.deb ./libecryptfs1_111-5_amd64.deb
@@ -80,6 +87,7 @@ apt-get install $1 ./ecryptfs-utils_111-5_amd64.deb ./libecryptfs1_111-5_amd64.d
 cp ./30-randomize-mac-address.conf /etc/NetworkManager/conf.d
 # baobab already installed in MX21
 apt-get -t experimental install $1 josm
+# qgis from ppa
 apt-get install $1 qgis qgis-plugin-grass qgis-server 
 #<-- nodejs
 curl -sL https://deb.nodesource.com/setup_14.x | bash -
@@ -89,4 +97,5 @@ echo "deb [signed-by=/usr/share/keyrings/yarnkey.gpg] https://dl.yarnpkg.com/deb
 apt-get update 
 apt-get install $1 yarn
 #--> nodejs
+# blivet-gui from ppa
 apt-get install $1 blivet-gui
\ No newline at end of file