User blog comment:DontDrinkH20/Some Explanations of Certain Large Cardinals/@comment-11227630-20181019090840/@comment-36540075-20181020194650

1. ok

2. Yes, some $\lambda$ can be $\lambda^+$-Mahlo (and every weakly compact cardinal is). It's called a "greatly Mahlo" cardinal.

3. $\Pi_0^1$-indescribable cardinals are precisely the inaccessible cardinals.

4. ok