Modern HTML5

Client-side form validation

HTML Tag validation

Use tag validation (type, min, max ...) with required if data is required.

<input type='username' name="username" min="2", max="12" required>

Use it for data-validation in form :

Input form with js

Use form with javascript for trigger input element.

<form onsubmit="myFunction()">
    Enter name : <input type="text" name="fname">
</form>

SEO

use OG meta for your social media SEO

<html xmlns:og="http://ogp.me/ns#">
    <head>
        <title>Open Graph : pourquoi utiliser les balises OGP ?</title>
        <meta property="og:title" content="Article sur l'Open Graph par Referenseo" />
        <meta property="og:type" content="article" />
        <meta property="og:url" content="http://www.yakaferci.com/open-graph/" />
        <meta property="og:image" content="http://referenseo/images/open-graph.jpg" />
        <meta property="og:site_name" content="Agence de référencement Referenseo" />
    </head>
</html>