AAMOI, OS locate gives me a two letter & six number location.
https://support.landmark.co.uk/hc/en-gb ... Conversion says:
6 numbers are accurate to a 100m squareUsing Google maps (zoomed in as close as it will go) shows me sat at the front wall of the house (I'm about 3m in). I decided to walk to the back room of the house. Nope, still in the front room. Walk to the window of the front room and . . . whoops, I'm outside, half way down the side alley. Playing with W3W gives a certain amount of indecision - but it could be that I'm on the 'border' of the square. I'm also losing enthusiasm.
Still, however, you look at it, claimed 9m, real (from my experience) 11m or not, they're still more accurate than claimed 100m. And if you're in a field, or along a little lane, footpath or track, good luck with getting GPS to give you a usable name for it. Right now, Filly is out going for the proverbial tramp in the woods. SSI or not, I doubt a post code is much use there!
Your 'standard' is how you drive alone, not how you drive during a test.