In many places, both on the Plusnet website and elsewhere, I see broadband speeds specified as so many Mb, e.g.
https://www.plus.net/home-broadband/package-guides/says "Up to 17Mb speeds". This is INCORRECT. The correct way would be:
"Up to 17 Mb/s speeds" or "Up to 17 Mbps speeds".
The reason should be obvious: "M" means "mega", "b" means "bit", so 17 Mb is NOT a speed; it is a quantity of data (seventeen megabits: just over two megabytes) . Mb/s or Mbps are the correct ways to state "megabits per second" which is what is meant. Writing Mb is, to me, a
clear declaration of ignorance.
BTW: at least it says Mb. not mb, which would mean millibits - obviously nonsense.
Further: in science and engineering, it is correct to put a space between the number and its unit symbol, for the same reason as putting a space between two words in a message in ordinary language. If you want to ensure that no new line occurs between the number and its unit symbol, use a non-breaking space, not an ordinary space.