I'm reading a technical documentation so every quirky detail, that a normal human being easily realizes to be a typo or just a less well chosen formulation, can, in fact, be a profound base for a concept and can fundamentally affect the future design.

In the said document I can find the term "*numeric digit*". What is this? Also, what is it not?

In my mind a digit is a character in the set of "*0123456789*", while something numeric is a a set of characters consisting of characters in the set of "*0123456789*" (yes, it's the same set).

Perhaps we can define the term in question by exclusion from all the other possible cases' definition. So what would be a good example of the following?

- a non-numeric digit
- a numeric non-digit
- a non-numeric non-digit

My guestimation is this.

- NST, unless we switch the base (which is too mathematical).
- NST, unless we declare a string of a digit (which is too programmatic).
- Anything sans digits (which is a superfluous tautology).

## Best Answer

It's just a number, 0-9, as you said. Use of the word "numeric" is just to specify 0-9 as opposed to, say, your thumb.