I need a few input elements, but their values won't be submitted anywhere - they're just going to be manipulated by some client-side JavaScript. Do I have to place them in a <form> to have legit HTML, or can they just be free-standing?
For additional information, in xhtml strict you have to place in one of these elements: "ins", "del", "h1", "h2", "h3", "h4", "h5", "h6", "p", "div", "address", "fieldset"
No. You only need a form if you're submitting to a server.
来源：https://stackoverflow.com/questions/2862050/in-proper-html-must-an-input-be-in-a-form