RFC 3986

To be more stringent in adhering to RFC 3986 (which reserves !, ', (, ), and *), even though these characters have no formalized URI delimiting uses.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/encodeURIComponent

lib/stringify.js

@@ -37,7 +37,7 @@ internals.stringify = function (obj, prefix, generateArrayPrefix) {
         typeof obj === 'number' ||
         typeof obj === 'boolean') {
 
-        return [encodeURIComponent(prefix) + '=' + encodeURIComponent(obj)];
+        return [Utils.fixedEncodeURIComponent(prefix) + '=' + Utils.fixedEncodeURIComponent(obj)];
     }
 
     var values = [];