social-meta-tag.html

<!-- Schema.org markup for Google+ -->
<meta itemprop="name" content="site name">
<meta itemprop="description" content="descripcion max 155 caracteres">
<meta itemprop="image" content="imagen">

<!-- Twitter Cards -->
<meta name="twitter:card" content="summary" />
<meta name="twitter:site" content="@usuario" />
<meta name="twitter:title" content="titulo" />
<meta name="twitter:description" content="descripcion max 140 caracteres" />
<meta name="twitter:creator" content="@creador">
<meta name="twitter:image" content="imagen" />

<!-- Open Graph data -->
<meta property="og:title" content="titulo" />
<meta property="og:type" content="website" />
<meta property="og:url" content="url" />
<meta property="og:image" content="imagen" />
<meta property="og:description" content="descripcion max 155 caracteres" />
<meta property="og:site_name" content="site name">
<!--<meta property="fb:admins" content="Facebook ID" /> -->