  A tetravalent $2$-arc-transitive graph of order $728$ is either the known
$7$-arc-transitive incidence graph of the classical generalized hexagon
$GH(3,3)$ or a normal cover of a $2$-transitive graph of order $182$ denoted
$A[182,1]$ or $A[182,2]$ in the $2009$ list of Poto\v{c}nik.
