SSMU LSE Sector Constituents

I was today years old when I found that SFOR.L was a constituent of the London Stock Exchange.
It appears to be in a sector called SSMU. I’m a bit unclear on what that is. Is there another list of constituents that are not in the FTSE 100/250/350, Small Cap, AIM 50/100/All Share and does anybody know where i may find a list of constituents?

Search for “London Stock Exchange instrument list” and you’ll find the list as an option in the reports section on the London Stock Exchange website.

Amazing. Thank you very much