Rephrased messages and comments

c4wled

@@ -102,7 +102,7 @@ while test $# -gt 0; do
         ;;
         *) # Unknown instance parameter.
             test -n "$host_list" && break
-            echo "Error: not a valid instance option (\"$1\")." >&2
+            echo "Error: not a valid instance selector (\"$1\")." >&2
             print_usage
             exit 1
         ;;
@@ -110,7 +110,7 @@ while test $# -gt 0; do
     shift
 done
 
-# Parse and execute command argument against given instances.
+# Parse and execute command argument for selected instances.
 for wled_host in $host_list; do
     case "$1" in
         on) # Switch on.