WordPress automatically adds its current Version number to the head section of the themes. If you view the source of a WordPress-based website, you may find out the WordPress version it is using.
Below given is the meta tag that carries that version information and can be spotted when you right-click and view source of a WordPress site:
<meta name="generator" content="WordPress 4.3.1" />
This extra information about CMS version is added by WordPress itself in order to ke...