Why would somebody want to remove WordPress version? Of course, there is absolutely no shame about showing it. Just that each version has its vulnerabilities and if someone knows which version of WordPress your site is running, hacking it becomes easier. It can be seen, by clicking View > Page source and finding meta name=”generator” line. Also it’s possible to make automatic scan over the internet to find certain version WordPress sites and then hack them.
Updating to newer version is one cure, although if you make a lot of sites without contract of updating them or you have no time for dealing with updating WordPress, following solution may be suitable for you. So here goes hiding (removing) WordPress version:
In your active theme’s header.php file find this line:
<meta name="generator" content="WordPress <?php bloginfo('version'); ?>" />
and replace it with
<meta name="generator" content="WordPress" />
You can remove generator completely using
<meta name="generator" content="" />
, but in respect to WordPress community it’s nice to keep reference.