Virtually rank-into-rank cardinal is the virtual version of a rank-into-rank cardinal, specifically Axiom I3. That is, the defining elementary embedding is not in V itself, but rather in a forcing extension of V. This weakens the cardinal substantially and makes it consistent with V=L.
Strength relative to other large cardinals Virtually rank-into-rank cardinal is stronger than ω-iterable cardinal, but weaker than ω-Erdos cardinal.
References Gitman, Victoria; Schindler, Ralf (December 2018). "Virtual large cardinals". Annals of Pure and Applied Logic. 169 (12): 1317–1334. doi:10.1016/j.apal.2018.08.005.
