When I was in high-school, my geography teacher, who at the time I considered to be a real nark (even though in the end I decided that she was a pretty decent old lady), used to rant at kids in the class for using the expression “Ks”. Like 30 Ks up the road.
She'd point out that K was a temperature unit, kelvin. She'd explain that the correct abbreviation was km, for kilometer.
I remember thinking she was a little pedantic at the time, but now I understand her frustration. It really pisses me off...
[snip even longer rant]
'mils' doesn't mean milliseconds.
'klms' doesn't mean kilometers.
Number of Meters: 1,000