What is the short for 30% opacity?

Question

You can also use 0.3 or even shorter just .3

Answer 1

What do you mean by 'short'? how could you make that even shorter?

Answer 2

As I wrote you can just write .3

Answer 3

30/100= 0.3

Answer 4

I'm aware of that, but could you add a [ANSWERED] or something to it next time? thanks (;