Even worse when it's actually 15Mb/s.

Which could be written as 15Mbps with no doubt whatsoever.

15 Mb·s⁻¹

Mb•Hz

Okay, this was way funnier than it has any right to be.

Мб and хз are both common acronyms in Russian, so this reads as “может быть, х** знает”, roughly: “maybe, f--- if I know”

Sorry mate, an old habit.

Perhaps we should insist on more from formatting from above. That's probably a post processing thing for ... gAI 8)

Old habit from where? Is this a personal preference or a lesser known convention?

Someone said physics, it's also very common in engineering. But academically and professionally, I've only seen it with superscript.

Used that a bunch in physics class in school. Makes it much easier to calculate with units since you simply add up the exponents of the units instead of having to consider the notation around the units.

Doesn't work well in pure text mediums.

Pretty common physics convention, uncommon when referring to data speeds but common for other things measured over time.