The following words may be used as keywords in future evolutions of the language, so using them as identifiers should be avoided to allow an easier adoption of those potential future versions:

implements
private
public
interface
package
protected
static

Use of these words as identifiers would produce an error in JavaScript strict mode code.

Noncompliant Code Example

var package = document.getElementsByName("foo"); // Noncompliant
var someData = { package: true };                // Compliant, as it is not used as an identifier here

Compliant Solution

var elements = document.getElementsByName("foo"); // Compliant