What is wrong with the syntax of the following, I can’t get it to appear at all?
Switch All_Off "All Off" <VANTAGE> {autoupdate="false",tcp=">[ON:10.5.1.6:3040:'MAP(off.map)'],>[OFF:10.5.1.6:3040:'MAP(off.map)']"}
The map file is in the proper location, I see no errors in the log.
Scratching my head 
What do you mean by [quote=“KidSquid, post:1, topic:12838”]
I can’t get it to appear at all
[/quote]
?
The definition in *.items does only the definition of the item, to let it show up in the UI, you will have to set up a line in *.sitemap.
It’s a good idea to change the order of bindings, autoupdate="false" should be the tail.
For icons it’s better to use lower case. I don’t know if it makes any difference, though
On Linux/OSX I’m pretty sure it won’t work unless it is all lower case. It might work on Windows.