Re: "Like I say, there’s no user guide to tell you what all the icons means."
Alistair, how hard is it to type:
“iphone x user guide”
into google, click on the first link that it provides (https://support.apple.com/en-gb/iphone-x), scroll down to where it says “Learn more” and click on the “iPhone User Guide” link (which gets you to http://help.apple.com/iphone/11/)?
It’s even item number 3 returned if you click on Support and then search using the same phrase on the Apple web site.