Notation for the class of all cardinals I have seen the notation for the class of all ordinals to be $\rm Ord$ or $\rm On$, is there an analogous notation for the class of all cardinals?

Nothing particular standard, but $\rm Card$ has been used before, I have seen $\Gamma(M)$ denoting the cardinals of a model $M$, although more in the context of failure of choice where this is a partial order.
Cantor originally used Tav (ת) the last letter of the Hebrew alphabet to denote the class of cardinals. But that didn't stick.
