You’ve had the misfortune to break down, you’re in a part of the country you don’t know, your on a single farm track with no-one and no road signs in site. How can you establish your whereabouts so that someone can come to your aid?
Find the menu option “Help Me!” on your TomTom. On mine it’s at the highest level, and on the first menu page. Press it.

From the options that appear press “Where am I?”

Your TomTom will then show you a small map, which can be zoomed in/out using the + and – symbols. Give you brief description of your location and, most usefully to other satnav users, your precise location expressed as longitude and latitude values.

This is far more accurate than a postcode, town or road. If expressed in decimal format, generally a value to 5 decimal places, which your TomTom shows, is to within 1 metre. And you don’t need to have remembered any B road number, unpronounceable Welsh name, etc.
You can either read this out or, probably better for avoiding misunderstandings, text it to a fellow SKCC’er, who will then have no difficulty finding you. See “How To … Navigate to a Location using Longitude/Latitude” if you don’t know how to do this.