"M" - "Mega" is an official general purpose SI prefix approved in 1960 which always stood for a decimal multiplier. Its common usage as a binary multiplier was limited to counting units of computer memory, and is purely an approximation to allow convenient speaking of, e.g., a megabyte of RAM instead of 1.048576 megabytes of RAM. Because it reflects the natural scale of physical memory.

It is more properly referred to as "MeB" - "mebi", which became an ISO standard prefix in 2008.

Interesting!

But hmm..."Megameter" "Megaliter" "Megagram"

Just a small correction: the abbreviated form of mebibyte is MiB.

Thanks!

There is already MiB (mebibytes) and MB (once actual megabytes, now what you call MMB).