  Thirty years ago, the present author discussed pure state unraveling
(stochastic quantum trajectories) of Markovian open system dynamics. The fact
that he considered all positive dynamics, not restricted for the
Lindblad-Gorini-Kossakowski-Sudarshan complete-positive subclass, has remained
unnoticed so far. Here we point out the importance of the transition rate
operator and the merit of invariant (representation-independent) approach, with
reference to invariant condition of positive dynamics and extension of quantum
state diffusion beyond complete-positive dynamics. A new result, description of
all diffusive unravelings of positive dynamics directly follows.
