AWOL:
Bnnnnnnnn
Is an Arduino nicety, and only good for eight bits, I think, and not portable.
0bxxxxx is a supported C "standard" ( I confess, I do not know its true standing), so should be reasonably portable, and goes beyond eight bits.
Though why anyone would consider expressing a literal of more than four bits in binary is beyond me.Personally, I think I prefer the "0bnnnnnnnn" notation because it mirrors the "0xnn" notation
But octal notation (leading zero) mirrors neither, and catches out many.
Edit:
Side note about the "beings with 10 fingers" comment
...but most people count on their fingers in unary. ( or up to 1023 for the binary-savvy)
So... what is octal notation?