I'm trying to alter my site in such a way so that when people view it, they don't know it's powered by Drupal. So, was wondering if there are any signs that give this away that I should know about?
Some of the giveaways I know of, are:
etc
I'm looking for similar stuff?
You can't really escape people's suspicions. To do so, you'd have to change file-systems, stylesheets, markup, etc. This is unreasonable. Why does it matter if you're using Drupal?
People who knows Drupal may identify it by the source. But Drupal has no Generator Header like Joomla or others.
Let's look at a fairly customized page based on Drupal: http://www.losttheatre.co.uk/ (a random page from a Drupal sites repository). There are many giveaways:
body) that do not change appearance - Drupal uses them to provide some info about the state of the page (like <body class="front not-logged-in page-front-page two-sidebars">)My advice is: don't try too hard with hiding the CMS of your website, if a hacker wants to find out what CMS you are running, he/she will find out. I'd focus on keeping the CMS up-to-date (Drupal makes this easy) and also watching out which modules you are installing - they are the most likely attack vectors.
Since this question is still getting many hits, let me update it with an example of a website of a major company (one of the biggest telephone companies in Poland), that, to my (pleasant) surprise ,is using Drupal for its main site, http://dialog.pl/:
/sites/all/themes/zen-dialog-main-page/../zen/css/page-strona_glowna.php or CSS styles applied: <body class="front not-logged-in node-type-page two-sidebars">As you can see, it's still possible to tell that the website is using Drupal - and this is a website of a major corporation. So the above advice still holds: don't waste your resources on trying to hide the CMS you used, keep it up to date (that's why the update.php file is probably still in place), monitor security vulnerabilities, use strong passwords, etc.
Like others have said, don't worry too much about this. It's a waste of time. Just keep Drupal core and all your modules up to date (you can even set it to email you when security releases are released for your installed modules) and you shouldn't have to worry about a thing.
Quick ways to find out if a site is a Drupal site.
There are a lot of other ways that indicate if a site is a Drupal site, but the above is fast and certain.
Other signs would be.
You're wasting your time:
Obscurity is not a form of security. And trying to hide Drupal may only tempt a hacker to beat you.
If there is a security flaw, you will almost certainly miss it and the hacker only has to try a specific attack vector. He or she is not going to check if it's Drupal or not. Your attack may come from software that won't care.
The changes you make to hide Drupal may actually make your site less secure. Especially if you change the core and are no longer able to tell if your site is up-to-date.
It's very likely that the effort you spend hiding Drupal can, instead be applied to a proven, effective security policy and get better results.
The expires headers are pretty unique as well. In fact they are set to Dries Buytaert (creator of Drupal) date of birth. As far as I can tell they have been set like the below since Drupal 4.6.
Expires: Sun, 19 Nov 1978 05:00:00 GMT
Dead giveaway:
Try going to update.php, you'll get Access Denied (and the Garland theme).