diff --git a/script/lib/chrooted_job_ubuntu.sh b/script/lib/chrooted_job_ubuntu.sh
index ce85d61..2d953ca 100644
--- a/script/lib/chrooted_job_ubuntu.sh
+++ b/script/lib/chrooted_job_ubuntu.sh
@@ -9,26 +9,30 @@ function chrooted_job() {
 	# Mount the rest of partitions by target /etc/fstab
 	mount -a
 
-	# Set up the kernel hook of encryption
+	# Prepare the crypto tool in the install target
 	echo "...Installing cryptsetup-initramfs package."
 	apt -qq install -y cryptsetup-initramfs
 
-	# Prepare a key file to embed in to the ramfs.
+	# Prepare a new key file to embed in to the ramfs.
+	# This new file contains a new key to open the LUKS volume. 
+	# The new key is 4096byte length binary value. 
+	# Because this key is sotred as "cleartext", in the target file sysmte,
+	# only root is allowed to access this key file. 
 	echo "...Prepairing key file."
 	mkdir /etc/luks
 	dd if=/dev/urandom of=/etc/luks/boot_os.keyfile bs=4096 count=1 status=none
 	chmod u=rx,go-rwx /etc/luks
 	chmod u=r,go-rwx /etc/luks/boot_os.keyfile
 
-	# Add a key to the key file. Use the passphrase in the environment variable. 
+	# Add the new key to the LUKS 2nd key slot. The passphrase is required to modify the LUKS keyslot.  
 	echo "...Adding a key to the key file."
 	printf %s "${PASSPHRASE}" | cryptsetup luksAddKey --iter-time "${ITERTIME}" -d - "${DEV}${CRYPTPARTITION}" /etc/luks/boot_os.keyfile
 
-	# Add the LUKS volume information to /etc/crypttab to decrypt by kernel.  
+	# Register the LUKS voluem to /etc/crypttab to tell "This volume is encrypted" 
 	echo "...Adding LUKS volume info to /etc/crypttab."
 	echo "${CRYPTPARTNAME} UUID=$(blkid -s UUID -o value ${DEV}${CRYPTPARTITION}) /etc/luks/boot_os.keyfile luks,discard" >> /etc/crypttab
 
-	# Putting key file into the ramfs initial image
+	# Add key file to the list of the intems in initfsram. 
 	echo "...Registering key file to the ramfs"
 	echo "KEYFILE_PATTERN=/etc/luks/*.keyfile" >> /etc/cryptsetup-initramfs/conf-hook
 	echo "UMASK=0077" >> /etc/initramfs-tools/initramfs.conf
diff --git a/script/lib/chrooted_job_void.sh b/script/lib/chrooted_job_void.sh
index 8482b01..2d50a73 100644
--- a/script/lib/chrooted_job_void.sh
+++ b/script/lib/chrooted_job_void.sh
@@ -6,39 +6,43 @@ source config.sh
 
 # Create a key file for LUKS and register it as contents of the initramfs image
 function chrooted_job() {
-		# Mount the rest of partitions by target /etc/fstab
-		mount -a
+	# Mount the rest of partitions by target /etc/fstab
+	mount -a
 
-		# Set up the kernel hook of encryption
-		echo "...Installing cryptsetup-initramfs package."
-		xbps-install -y lvm2 cryptsetup
+	# Prepare the crypto tool in the install target
+	echo "...Installing cryptsetup-initramfs package."
+	xbps-install -y lvm2 cryptsetup
 
-		# Prepare a key file to embed in to the ramfs.
-		echo "...Prepairing key file."
-		mkdir /etc/luks
-		dd if=/dev/urandom of=/etc/luks/boot_os.keyfile bs=4096 count=1 status=none
-		chmod u=rx,go-rwx /etc/luks
-		chmod u=r,go-rwx /etc/luks/boot_os.keyfile
+	# Prepare a new key file to embed in to the ramfs.
+	# This new file contains a new key to open the LUKS volume. 
+	# The new key is 4096byte length binary value. 
+	# Because this key is sotred as "cleartext", in the target file sysmte,
+	# only root is allowed to access this key file. 
+	echo "...Prepairing key file."
+	mkdir /etc/luks
+	dd if=/dev/urandom of=/etc/luks/boot_os.keyfile bs=4096 count=1 status=none
+	chmod u=rx,go-rwx /etc/luks
+	chmod u=r,go-rwx /etc/luks/boot_os.keyfile
 
-		# Add a key to the key file. Use the passphrase in the environment variable. 
-		echo "...Adding a key to the key file."
-		printf %s "${PASSPHRASE}" | cryptsetup luksAddKey --iter-time "${ITERTIME}" -d - "${DEV}${CRYPTPARTITION}" /etc/luks/boot_os.keyfile
+	# Add the new key to the LUKS 2nd key slot. The passphrase is required to modify the LUKS keyslot.  
+	echo "...Adding a key to the key file."
+	printf %s "${PASSPHRASE}" | cryptsetup luksAddKey --iter-time "${ITERTIME}" -d - "${DEV}${CRYPTPARTITION}" /etc/luks/boot_os.keyfile
 
-		# Add the LUKS volume information to /etc/crypttab to decrypt by kernel.  
-		echo "...Adding LUKS volume info to /etc/crypttab."
-		echo "${CRYPTPARTNAME} UUID=$(blkid -s UUID -o value ${DEV}${CRYPTPARTITION}) /etc/luks/boot_os.keyfile luks,discard" >> /etc/crypttab
+	# Register the LUKS voluem to /etc/crypttab to tell "This volume is encrypted" 
+	echo "...Adding LUKS volume info to /etc/crypttab."
+	echo "${CRYPTPARTNAME} UUID=$(blkid -s UUID -o value ${DEV}${CRYPTPARTITION}) /etc/luks/boot_os.keyfile luks,discard" >> /etc/crypttab
 
-		# Putting key file into the ramfs initial image
-		echo "...Registering key file to the ramfs"
-		echo 'install_items+=" /etc/luks/boot_os.keyfile /etc/crypttab " ' > /etc/dracut.conf.d/10-crypt.conf
+	# Add key file to the list of the intems in initfsram. 
+	echo "...Registering key file to the ramfs"
+	echo 'install_items+=" /etc/luks/boot_os.keyfile /etc/crypttab " ' > /etc/dracut.conf.d/10-crypt.conf
 
-		# Finally, update the ramfs initial image with the key file. 
-		echo "...Upadting initramfs."
-		xbps-reconfigure -fa
-		echo "...grub-mkconfig."
-		grub-mkconfig -o /boot/grub/grub.cfg
+	# Finally, update the ramfs initial image with the key file. 
+	echo "...Upadting initramfs."
+	xbps-reconfigure -fa
+	echo "...grub-mkconfig."
+	grub-mkconfig -o /boot/grub/grub.cfg
 
-		# Leave chroot
+	# Leave chroot
 }
 
 # Execute job
diff --git a/script/lib/common.sh b/script/lib/common.sh
index 4f732b8..ec076b5 100644
--- a/script/lib/common.sh
+++ b/script/lib/common.sh
@@ -298,14 +298,15 @@ function post_install() {
 	echo "...Mounting all other dirs."
 	for n in proc sys dev tmp etc/resolv.conf; do mount --rbind "/$n" "${TARGETMOUNTPOINT}/$n"; done
 
-	# Copy all scripts to the target /tmp to in chroot session. 
+	# Copy all scripts to the target /tmp for using in chroot session. 
 	echo "...Copy files in current dir to ${TARGETMOUNTPOINT}/tmp."
 	mkdir "${TARGETMOUNTPOINT}/tmp/kaiten-yaki"
 	cp -r ./* -t "${TARGETMOUNTPOINT}/tmp/kaiten-yaki"
 
 	# Change root and create the keyfile and ramfs image for Linux kernel. 
-	# The here document is script executed under chroot. And here we call 
-	# the distribution dependent script "lib/chrooted_job_${DISTRIBUTIONSIGNATURE}.sh".
+	# The here-document is script executed under chroot. At here we call 
+	# the distribution dependent script "lib/chrooted_job_${DISTRIBUTIONSIGNATURE}.sh",
+	# which was copied to /temp at previous code.
 	echo "...Chroot to ${TARGETMOUNTPOINT}. and execute chrooted_job_${DISTRIBUTIONSIGNATURE}.sh"
 	# shellcheck disable=SC2086
 	cat <<- HEREDOC | chroot "${TARGETMOUNTPOINT}" /bin/bash