TITLE: What is the symbol to refer to the set of whole numbers
QUESTION [14 upvotes]: The set of integers and natural numbers have symbols for them:

$\mathbb{Z}$ = integers = {$\ldots, -2, -1, 0, 1, 2, \ldots$}
$\mathbb{N}$ = natural numbers ($\mathbb{Z^+}$)  = {$1, 2, 3, \ldots$}

Even though there appears to be some confusion as to exactly What are the "whole numbers"?, my question is what is the symbol to represent the set $0, 1, 2, \ldots $.  I have not seen $\mathbb{W}$  used so wondering if there is another symbol for this set, or if this set does not have an official symbol associated with it.

REPLY [4 votes]: Except $\mathbb{N}\cup\{0\}$ we use $\mathbb{I}$ symbol too for $\{0,1,2,3,...\}$ and we call it the set of calculating numbers that it has only zero more than natural numbers. Also in some books it has been denoted by $\mathbb{Z}^{\geq0}$