diff --git a/seqs/backup.sh b/seqs/backup.sh
index 53609ae..9336741 100755
--- a/seqs/backup.sh
+++ b/seqs/backup.sh
@@ -1,8 +1,9 @@
 #!/bin/bash
 
-readonly toolName=backup
-readonly toolBin=rsync
+# shellcheck disable=SC2001 # See if you can use ${variable//search/replace} instead.
+#                             It is more easy with sed to remove multiple trailing /
 
+sq_toolBin=rsync
 sq_aptOpt=
 sq_config=0
 
@@ -30,7 +31,7 @@ step_1() {
   local buTarget="/backup"
   if (( ! sq_config )) ; then
     error -e "Cannot backup root without properly configured excludes"
-    error -e "     (expected config: ${seq_configFile})"
+    error -e "     (expected config: ${seq_configFile:?})"
   else
     buTarget="$BACKUP_TARGET"
   fi
@@ -44,8 +45,8 @@ step_1() {
 step_3_info() { 
   # Backup single directory recursively
   local opt=
-  local dir=
-  local tar=
+  local dir='<SOURCE>'
+  local tar='[TARGET]'
   local exc=
   shift
   if [ "${1:-}" == "-t" ] ; then
@@ -55,14 +56,14 @@ step_3_info() {
   if [ -n "${1:-}" ] ; then
     dir="$1"
     shift
-    if [ -z $opt ] && [ -n "$1" ] ; then
+    if [ -z "$opt" ] && [ -n "$1" ] ; then
       tar="$1"
       shift
     else
       tar="$BACKUP_TARGET"
     fi
     if [ -n "${1:-}" ] ; then
-      exc="$@"
+      exc="$*"
     else
       exc="[NO EXCLUDES]"
     fi
@@ -102,26 +103,26 @@ step_3() {
     exit 1
   fi
 
-  buLog=$(basename $1)
+  buLog="$(basename -- "$1")"
   if [ "$buLog" == "/" ] ; then
     buLog="root"
     buSource="$1"
   else
     # remove trailing slashes
-    buSource=$(echo "$1" | sed 's:/*$::')
+    buSource="$(echo "$1" | sed 's:/*$::')"
   fi
   buLog="backup_${buLog}"
   shift
 
-  if [ $configTarget -ne 0 ] && (( sq_config )) ; then
+  if (( configTarget )) && (( sq_config )) ; then
     # Taking target from config
-    buTarget=$(echo "$BACKUP_TARGET" | sed 's:/*$::')
+    buTarget="$(echo "$BACKUP_TARGET" | sed 's:/*$::')"
   else
     if [ -z "$1" ] ; then
       error -e "No valid target found"
       exit 1
     fi
-    buTarget=$(echo "$1" | sed 's:/*$::')
+    buTarget="$(echo "$1" | sed 's:/*$::')"
     shift
   fi
   if [ ! -d "${buTarget}" ] && [ ! -L "${buTarget}" ]
@@ -136,11 +137,13 @@ step_3() {
 
   info "Source  : $buSource"
   info "Target  : $buTarget"
-  info "Excludes: $@"
+  info "Excludes: $*"
 
   #fix doubling trailing slash on verbose output when backing up root
   local tmpSource="$buSource/"
-  local tmpTarget="${buTarget}/$(basename ${buSource})"
+  local tmpTarget=
+
+  tmpTarget="${buTarget}/$(basename -- "${buSource}")"
   if [ "$buSource" == "/" ] ; then
     tmpSource="/"
     tmpTarget="${buTarget}/"
@@ -159,26 +162,25 @@ step_3() {
 
   checkInstalled 
   exep "mv -f ${buTarget}/${buLog}0.log /tmp/${buLog}1.log 2>/dev/null"
-  exep "$toolBin -avxHAX --delete --info=stats2 ${buExcludes[*]} ${tmpSource} ${tmpTarget} > /tmp/${buLog}0.log"
+  exep "${sq_toolBin} -avxHAX --delete --info=stats2 ${buExcludes[*]} ${tmpSource} ${tmpTarget} > /tmp/${buLog}0.log"
 
-  exe mv -f /tmp/${buLog}*.log ${buTarget}
+  exe mv -f /tmp/"${buLog}"*.log "${buTarget}"
   exe sync
   exep "mount -o ro,remount '${buTarget}' >>/dev/null 2>&1"
 }
 
-step_100_info() { echo "Install $toolBin"; }
+step_100_info() { echo "Install ${sq_toolBin}"; }
 step_100_alias() { echo "install"; }
 step_100() {
   exe apt update
-  exe apt install $toolBin ${sq_aptOpt}
+  exe apt install ${sq_toolBin} ${sq_aptOpt}
 }
 
 checkInstalled() {
-  command -v $toolBin >>/dev/null
-  if [ $? -ne 0 ] ; then
+  if ! command -v ${sq_toolBin} >>/dev/null ; then
     step install
   fi
-  toolBin="$(command -v $toolBin)"
+  sq_toolBin="$(command -v ${sq_toolBin})"
 }
 
 # shellcheck disable=SC2034 # Appears unused