Comment by hilbert42
"People have used all sorts of abbreviations for the SI prefixes and SI units for as long as I can remember."
In the US that is, not in metric counties that use SI by default.
For those in the US (and to a lesser extent the UK) there are multiple metric systems. The other notable system that's still in use is the cgs (centimetre–gram–second) system.
'cgs units' are still used in some areas notably physics as they can make calculations easier, there they're called Gaussian-cgs units.
Incidentally, often, as here, 'cgs' is in lowercase to reflect the case of the units' abbreviations. That said, the uppercase abbreviation is also often used. For instance, as I typed this my browser kept correcting the lowercase to 'CGS'.
> In the US that is, not in metric counties that use the SI system by default.
India which metricated in the late 1950s is still a big (ab)user of poor SI symbolism. A lot of the 'cms', 'gms', 'cc', 'kgs', etc come from Indian writers and Indian publications (case in point: the article in this thread).
> The other notable system that's still in use is the cgs (centimetre–gram–second) system.
> 'cgs units' are still used in some areas notably physics as they can make calculations easier, there they're called Gaussian-cgs units.
I'm not sure they're used all that much—I was under the impression most CGS units fell out of favour as MKS and eventually SI took over. I was an RA at my physics department for a while and we used SI as much as we could. Some specialisations use a certain form of natural units (like geometrised units in general relativity), but by and large SI dominated.