It is very near the bottom of Kanamori's chart. The very bottom is that of a (strongly) inaccessible cardinals, which is the smallest large cardinal axiom. Right above the inaccessible in the chart is &alpha;-inaccessible. It turns out that the Universe Axiom (UA) is strictly weaker than the existence of a 2-inaccessible cardinal. In fact, &kappa; is 2-inaccessible if and only if V<sub>&kappa;</sub> &#8871; ZFC + UA.

Specifically, a cardinal &kappa; is:

* *0-inaccessible* iff &kappa; is regular,
* *1-inaccessible* iff &kappa; is a regular strong limit of 0-inaccessibles,
* *2-inaccessible* iff &kappa; is a regular strong limit of 1-inaccessibles,
* etc.

So an inaccessible cardinal is exactly the same as a 1-inaccessible, which are also the cardinals &kappa; such that V<sub>&kappa;</sub> &#8871; ZFC. If &kappa; is 2-inaccessible, then there are unboundedly many inaccessibles &lambda; < &kappa;. These are inaccessible in V<sub>&kappa;</sub> too, which is why V<sub>&kappa;</sub> satisfies UA.