I like /s for bytes and ps for bits. 100Mbps = 100 million bits per second. 100MB/s = 100 million bytes per second. (The capitalization is important of course. I tried writing some examples where it's not preserved and it's too weird. I tend to not use capital letters on things like Slack, but for bytes, you just have to. The difference between milli and Mega can also be important, but since nobody talks about the negative powers with bandwidth, you are probably OK if your shift key breaks.)