Originally Posted by meme
I believe 'user agent' is the software used to display your page. In this case Qt as used by Sigil, but it could be Firefox, IE, or the software on your ereader device.
These settings can, I believe, be overridden if you define them in your stylesheet. You'll also notice they are there if you do not link any stylesheet to your page.
Thanks meme for your reply, sorry I'm lost, I'm just using Sigil to create my "ebook", I'm not using any other apps to display it, as you can see on my previous post, the webkit tag is shown in Sigil. Is there anyway I can remove/deactivate it in my CSS (not just the tag but all of the user agent's stylesheet)? It seems to me that there are a bunch of other tags created by this user agent, it would be simpler just to deactivate it completely in my CSS if possible and I'll define my own tags/rules as needed.