A nontaxable return refers to a type of income or money that you don't have to pay taxes on. It means you won't be taxed on that money when you file your tax return. Full definition
From a tax perspective, any distributions from the Fund that might occur will be characterized as nontaxable return of capital (lowering the investor's cost basis). (proshares.com)
This rule does not apply to nontaxable return of capital distributions. (fairmark.com)
The portion of each withdrawal that is subject to taxes and penalties is prorated based on the portion of the total account balance that comes from earnings; the rest is a nontaxable return of contributions. (baltimoresun.com)