Let $\Gamma$ be a directed graph on $n$ vertices with at most $2n - 4$ edges. Is $\Gamma$ embeddable in its complement?
In other words, does there exist a bijection $\alpha$ of $V(\Gamma)$ such that $(x,y) \in E(\Gamma)$ implies $(\alpha(x), \alpha(y)) \not\in E(\Gamma)$?
This property is known to hold for undirected graphs (on $n$ vertices with at most $n-2$ edges) by Burns and Schuster.