diff --git a/include/functions b/include/functions
index db7f5359..7f193aa5 100644
--- a/include/functions
+++ b/include/functions
@@ -3052,12 +3052,12 @@
 
     SafeInput() {
         exitcode=1
-        # By default remove only special or undefined characters
+        # Test against the string with a generic test set
         if [ $# -eq 1 ]; then
             input="$1"
-            # Allow only a common set of characters in first parameter
-            cleaned=$(echo "$input" | sed 's/[^a-zA-Z0-9\._:=-]//g')
-        # If know what to test against, then see if input matches the specified class
+            # Only allow common set of characters: a-z, A-Z, 0-9, /._-:=
+            cleaned=$(echo "$input" | sed 's/[^a-zA-Z0-9\/\._:=-]//g')
+        # If two parameters are specified, then test input against specified class
         elif [ $# -eq 2 ]; then
             input="$1"
             testchars="$2"